Which statement is true about oxygen-17 and oxygen-18? A Their atoms have identical masses B They do not have the same number of protons C They have different numbers of electrons D They are isotopes of oxygen

Answers

Answer 1

Answer:

option d

Explanation:

isotope means atoms with different mass no. 17 and 18 written on the left represent mass number

this is because atoms can differ in mass no.

option a is incorrect as they have different mass no,hence,different massoption b is incorrect as atoms-oxygen-17 and oxygen 18-of same element    oxygen cannot differ in no of protonsif they had different no of electons they would have a charge like -1,-2,etcoption d is correct,because atoms can differ in mass no.   isotope means atoms with different mass no. 17 and 18 written on the left represent mass number                                                      

Related Questions

Question 18 of 25
How is the atomic number related to core electrons?
O A. The atomic number is equal to the number of core electrons.
O B. The atomic number minus the period number is the number of
core electrons.
O C. The atomic number plus the group number is the number of core
electrons.
O D. The number of valence electrons plus core electrons is the atomic
number

Answers

Answer:

D

Explanation:

If the atom is neutral, the sum of the core and valence electrons is the same as the number of protons, which is the atomic number of the element. So if the sum of the core and valence electrons in a neutral atom equals 25 , that is the number of protons in the atomic nucleus, and the atomic number of the element.

The number of valence electrons plus core electrons is the atomic number.

How is the atomic number related to the variety of electrons?

The variety of protons, neutrons, and electrons in an atom may be determined from a set of easy guidelines. The wide variety of protons within the nucleus of the atom is equal to the atomic quantity (Z). The quantity of electrons in an impartial atom is identical to the number of protons.

What's an atomic number associated with?

The variety of protons in a nucleus is called the atomic variety and usually equals the number of electrons in orbit approximately that nucleus (in a nonionized atom). For this reason, all atoms which have an equally wide variety of protons and the atomic range are atoms of the equal element.

Learn more about atomic numbers here https://brainly.com/question/1805828

#SPJ2

Which two features of Earth's crust involve tension?
O A. Convergent boundaries
B. Reverse faults
c. Divergent boundaries
O D. Normal faults

Answers

Answer:

The correct options are;

C. Divergent plate boundary

D. Normal faults

Explanation:

Tensile stress tends to pull objects part by acting axially upon the object to pull the object on a cross section perpendicular to the objects cross-section

The most common stress in convergent plate boundaries is compression stress

The most common stress in divergent plate boundaries is tensile stress

In the presence of tensile stress, normal faults results in the raising of mountains due to their enormous forces

Therefore, the features of Earth's crust involving tension are divergent plate boundary and normal faults.

Answer:c and d

Explanation:

For a system, H2(g) + I2(g) ⇌ 2 HI(g), Kc = 62.9 at 750 K. 2.80 moles of HI were placed in a 10.0-liter container, brought up to 750 K, and allowed to come to equilibrium. Which situation described below is true, at equilibrium?
a. [HI] = 2 × [H2]
b. [HI] = [H2]
c. [HI] < [H2]
d. [HI] > [H2]
e. [H2] > [I2]

Answers

Answer:

d. [HI] > [H2]

Explanation:

The explanation at equilibrium is shown below:-

Data provided           [tex]H_2(g) + I(g) \rightleftharpoons 2HI_(g)[/tex]

Initial concentration    -           -           [tex]\frac{2.80}{10}[/tex] = 0.280 M

At equilibrium             x          x       0.280 - 2x

[tex]K_c = \frac{(HI)^2}{(H_2)(I_2)} = 62.9[/tex]

[tex]= \frac{(0.280 - 2x)^2}{x^2} = 62.9\\\\4x^2 - 1.12x + 0.0784 = 62.9x^2[/tex]

After solve the above equation we will get

x = 0.0282 M

Therefore at equilibrium

[tex][H_2] = [I_2] = x = 0.0282M\\\\[/tex]

[tex][HI] = 0.280 - 2x = 0.2236 M[/tex]

Hence, the correct option is d.

In the reaction below green chlorine gas and brown
iodine chloride forms yellow iodine trichloride
Cl2 (g) + ICI () = IC13 (s)
If some chlorine is removed from the reaction, how will
it affect the color of the mixture?
A. It will become more green.
B. It will become more yellow.
C. It will become more brown.
OD. It will not change.​

Answers

Answer:

The correct option is;

C. It will become more brown

Explanation:

Given that the reaction is as follows;

Cl₂(g) + ICl (g) ⇄ ICl₃

We have that the reaction and a decrease in the concentration of the reactants will favor the reverse reaction that is the decomposition of the yellow iodine trichloride and the formation of green chlorine gas and brown iodine chloride

Given that some green chlorine gas, which is part of the reactant, will be removed, the reverse reaction will be favored and initial concentration of the yellow iodine trichloride and the green chlorine gas will be reduced while the proportional concentration of the brown iodine chloride will increase and the mixture will become more brown.

Answer:

become more green

Explanation:

when humans burn fossil fuels, most of the the carbon quickly enters the atmosphere as carbon dioxide in the atmosphere in the process called
•transpiration
•combustion
•decomposition
•photosynthesis ​

Answers

transpiration i think
Pretty sure it’s combustion. The typical equation looks like this:

Any amount of Hydrocarbons (CH4 and C2H6 and are examples of them) plus Oxygen gas (O2) will ALWAYS yield Carbon Dioxide gas and Steam

If a had a number that was 12.47, what would be the answer rounded to 2 sig figs?

Answers

12

Explanation:

Look at the number directly after the number you want to keep. I'm your case you want to keep the first two numbers and the number directly after is 4 so there is no need to round up. Keep your 12 without a decimal.

The coefficients in a chemical equation represent
the
Select one:
a. masses, in grams, of all reactants and
products,
O b. relative numbers of moles of reactants and
products,
c. number of atoms in each compound in a
reaction.
O d. number of valence electrons involved in the
reaction

Answers

Answer:

the answer is C

''number of atoms in each compound in a  reaction.''

Explanation:

its a fact

The coefficients in the chemical equation represent relative numbers of moles of reactants and products. Therefore, option B is correct.

What is the chemical equation?

A chemical equation can be explained as the representation of a chemical reaction in terms of chemical symbols. A chemical equation exhibits reactants participating, formed products in the reaction, and an arrow representing the direction of the chemical reaction.

The chemical equation in which the number of atoms of each element is equal on both sides of the chemical equation is known as a balanced chemical equation.

The law of conservation of matter needed to be followed while balancing a chemical equation.

The total mass of all elements on the reactant side should be equal to the total mass of all elements on the product side in a balanced chemical equation. The coefficients represent a number of moles of reactants and products.

Learn more about the chemical equation, here:

brainly.com/question/28294176

#SPJ2

A number should be rounded up if
it is the first digit
b. the number after it is between 0 and 4
the number after it is between 5 and 9
d. it is the last digit
Please select the best answer from the choices prou

Answers

Answer:

C.) The number after it is between 5 and 9

Explanation:

If the digit to the right is less than five, you must leave the digit you want to round to as it is.

But, if the digit to the right is greater than or equal to five, you must increase the value of the digit you're rounding to by one. And any remaining digits before the decimal point become zeros, and any that are after the decimal point are dropped.

Hope this helps you out! : )

) What mass of potassium nitrate would be needed to
produce a saturated solution of potassium nitrate in
50 grams of water at 313 K?​

Answers

Answer:

the mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K is

[tex]31g[/tex]

Explanation:

To determine the mass of potassium nitrate needed to

produce a saturated solution of potassium nitrate in 50 grams of water at 313 K?, then it implies that we need to determine the

solubility of KNO3 is 62g KNO3 in 100g H2O at 313K. And this simply the amount of solute that when it dissolved in that water, then the water will not be able to take more solute again which means it has been saturated.that is the maximum quantity that the water can take at 313K.

If the solubility of KNO3 is 62g KNO3 in 100g H2O at temperature 313K

Then 50 g of water contains potassium nitrate = (62/100 X 50) at 313k = 31g

Therefore, the mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K is

31g

What is the unit charge on each subatomic particles

Answers

Answer:

Protons, Electrons, Neutrons

Explanation:

Neutron: 0 or Neutral

Electron: -1 or Negative

Proton: +1 or Positive

For proton and neutron look at neutr for neutral and p for positive

Answer:

❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️

The answer is Protons, Electrons, Neutrons

There is three of them.....

Hope this will help you

❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️❤️

Explanation:

Characteristic 1: a scar due to an injury

Characteristic 2: the shape of a person's face

Which characteristic is a trait that can be inherited? Explain your answer.

Answers

Characteristic 2: face shape. Another family member say a grandmother for example may have the same face shape so your DNA will dictate that same face shape.

Answer:

Only characteristics that are coded for by genes can be inherited. The shape of a person's face is inherited because this characteristic is coded for by genes. Characteristics that are due to environmental factors cannot be inherited. A scar due to an injury cannot be inherited because this characteristic is a result of an environmental factor.

Explanation:

sample response

example of nobel gas​

Answers

Answer:

helium , krypton,xenon,radon, argon are noble gasses

Helium Two examples would be helium and argon.

what is a chemical bond? an attractive force between 2 molecules

Answers

Answer:

The chemical bond between 2 molecules is called an intermolecular force.

Answer:

Chemical Bond:

Attraction between two atoms results in the formation of a bond which is called a chemical bond.

Inter molecular Forces:

Attractive Force that in between 2 molecules is called Inter molecular Forces. (Inter : Between)

Describe how red shifts were used by cosmologists to determine that the universe was expanding. How
is this evidence for the big bang theory?

Answers

Explanation:

astronomers have discover that in general the future of a Galaxy is, the more redshift light is this mean that the further away the Galaxy are the faster they are moving this is similar to explosion where the bits moving fastest travel for furthest on the explosion redshift data provides evidence that the universe including space itself is expanding .

What is the [H+] in a solution with pOH of 0.253? A. 5.58 × 10−15 M B. 1.79 × 10−14 M C. 3.21 × 10−2 M D. 5.58 × 10−1 M

Answers

Answer:

The answer is option B

Explanation:

To find [H+] in the solution we must first find the pH

That's

pH = - log[H+]

pH + pOH = 14

pOH = 0.253

pH = 14 - 0.253

pH = 13.747

Since we've found the pH we can now find the [H+] in the solution

We have

pH = - log[H+]

13.747 = - log[H+]

Take antilog of both sides

We have the final answer as

[tex][H+] = 1.79 \times {10}^{ - 14} M[/tex]

Hope this helps you

Answer:

Okay so we know that pOH + pH = 14, so if pOH is 0.253 the pH would be 13.747.  

And pH = -log [H+], so [H+] = 10^(-pH) -->This is just the antillog...  

so [H+] = 1.791e-14, which would make sense for the strongly basic solution (so B is the correct answer)  

Hope this helps...

How many valence electrons do the alkaline earth metals have?
O A. 6
O B. 2
O C. 4
O D. 8

Answers

Answer:

[tex]\boxed{2}[/tex]

Explanation:

Alkaline earth metals are in group 2. The number of valence electrons of elements in group 2 is 2.

2 valence electrons do the alkaline earth metals have. Therefore, option B is correct.

Alkaline earth metals are the elements in Group 2 of the periodic table, which includes beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

In general, elements in Group 2 have two valence electrons. Valence electrons are the electrons located in the outermost energy level (or shell) of an atom. For the alkaline earth metals, the outermost energy level is the second energy level, which can hold up to 8 electrons.

Only the two electrons in the s sublevel of the second energy level are considered valence electrons. These two valence electrons are involved in chemical reactions and bonding.

To learn more about the alkaline earth metals, follow the link:

https://brainly.com/question/32381670

#SPJ6

Adding a base to a solution would...?

Answers

Answer:

it would decrease [h+]

Explanation:

 This is due to  neutralization If a base is added to an acidic solution, the solution becomes less acidic and its position changes to the middle of the pH scale.

hope this helps

Answer:

Raise the pH

decrease [H+]

Explanation:

=> Adding base would raise the pH (Bases have more pH and Acids have less pH)

=> Adding base would decrease the concentration of [H+] ions as it contains hydroxyl ions which neutralized with H+ ions so as a result the concentration of [H+] ions decreases.

You arrive at a crime scene and are told the body of the victim is at the bottom of a pool that is 10 m deep. You walk over to what you are told is a 12 m in diameter, cylindrical pool. From the outside of the pool, you can see that the body looks badly burnt. Your partner says, “It looks like our victim had been burned alive and tried to put out the fire by jumping in the pool. The victim likely drowned to death.” Something does not sit right with you though. If there was a fire, where did it start? There are no signs of combustion anywhere. You aren’t so sure and ask the crime scene investigator to run a sample of the pool water before letting anybody try to pull the body out. The CSI comes back to you and tells you that normal pool water pH is roughly around 7.2, but the pool pH is actually highly basic at a level of 13, with a concentration of hydroxide ions at 1.0 x 10-1 mol/L. It becomes obvious to you that the body wasn’t burned before going in to the pool, but AFTER, and there was no fire needed! You order the body to be removed from the pool, but the CSI interjects, “It would be too dangerous with a pH that high. I suggest you get some vinegar from the store and pour it in to the pool beforehand to drop the pH to 7. Draining the pool would take far too long and we need to examine the body as soon as possible.” She asks one of your constables to go to the store to purchase five 4L jugs of vinegar (pH = 2) to pour in the pool, as she states it is enough to bring the pH to a safe level of 7. It sounds like it could be enough vinegar based on your knowledge of acids and bases, but you want to double-check her estimate before sending your constable to the store. Verify whether or not she is correct using calculations. A diagram may help you with your calculations. Hint 1: 1m3 = 1000L Hint 2: Vcylinder = πr2h

Answers

Answer:

The vinegar is not enough to neutralize the pool.

Explanation:

The [OH⁻] in the pool is 1.0x10⁻¹mol / L. To know how many moles of OH⁻ are in the solution, you must calculate volume of the pool thus:

V(pool) = πr²h

Where radius is d/2 = 12m/2 = 6m

and h is deep of the pool = 10m

V(pool) = π(6m)²*10

V(pool) = 1131m³

As 1m³ = 1000L:

1131000L in the pool. And moles of OH⁻ are:

1.0x10⁻¹mol / L ₓ 1131000L = 131100 moles of OH⁻ are in the pool

The neutralization of OH⁻ with H⁺ is:

OH⁻ + H⁺ → H₂O

To neutralize the pool you must add 131100 moles of H⁺.

The H⁺ concentration in a vinegar pH = 2 is:

pH = -log [H⁺]

2 = -log [H⁺]

1x10⁻²M = [H⁺]

4L are just 4x10⁻² moles of [H⁺]. That means:

The vinegar is not enough to neutralize the pool.

please help !!!
How much of KCIO3, must be heated to produce as much O2, as required to burn 24 g of carbon?​

Answers

Answer:

2KClO3 》》2KCl +3O2

C+ O2》》CO2

number of C moles

Required O2 moles (According to the mole ratio )

Relevant to the first equation, find the moles the KClO3, which is used to produce that amount of O2 moles

Now you can find the mass of KClO3

I mentioned the useful steps which can guide you to get the answer.

Explanation:

Which action destroys topsoil?

Answers

Answer:

I think it erosion

Explanation:

Well erosion washes away top soil

Eczema is a type of skin disease that appears as rashes or swelling. Eczema causes skin irritation or itchiness. What type of tissue does eczema affect? A. nervous B. muscle C. epithelial D. connective

Answers

I have sister with this skin disease so the answer is C. Epithelial. Eczema affects the Epithelial tissue.

How to know number of proton/electron from ionisation energy?

also how to know ionisation energy from number of electron?

How to know group of element? (like Iodine - group 17)​

Answers

Answer:

Ionization energy decreases from top to bottom in groups as the size of the atom becomes larger. For example, the first ionization energy of hydrogen is 1310 kJ mol⁻¹. The first ionization energy of lithium is 519 kJ mol⁻¹. Because lithium is a bigger atom and has more protons than hydrogen, its ionization energy is lower. So, in groups, the lower the ionization energy, the larger the atom and the more protons/electrons it has.

Ionization energy also increases from left to right across a period. The more protons in the nucleus, the greater the attraction between the nucleus and the electrons, which makes it more difficult to remove electrons. Helium has an ionization energy of 2370 kJ mol⁻¹ while hydrogen has an ionization energy of 1310 kJ mol⁻¹ because helium's nucleus has 2 protons attracting electrons instead of 1 like hydrogen. So for periods, the higher the ionization energy, the smaller the atom and the more protons/electrons it has.

Ionization energy is the energy required to remove an electron from its orbital around an atom. It increases across a period because the number of protons in the nucleus increases. This creates a stronger attraction between the nucleus and electrons, causing the electrons to be held tighter by the higher nuclear charge. Because the electrons are more difficult to remove, more energy is required which causes the ionization energy to be higher. So for periods, the more electrons the atom has, the higher the ionization energy. Ionization energy decreases down a group because the first electron removed is farther from the nucleus as the number of protons increases. Being farther away from the nucleus makes it easier for the electron to be pulled off as it is more loosely bounded, so less energy is required to remove the electron which causes the ionization energy to be lower. So for groups, the more electrons the atom has, the lower the ionization energy.

Groups are vertical columns going down on the periodic table. If you look at a periodic table, across the top, you will see the numbers 1-18. Those numbers signify the 18 groups of the periodic table. Iodine is a halogen so it is under Group 17 to the far right of the periodic table.

I attached two periodic tables for reference to everything that I've said as I've written a lot. Hope that helps.

How many moles is 25g of ammonia (NH3) pls show steps and answere asap

Answers

Answer:

Explanation:

Note

I'm using rounded numbers. Every periodic table is different. Use yours to correct my approximations.

1 mole of NH3

N =       14

H = 1

3 H =     3

==========

1 mole = 17 grams

Number of moles in 25 grams

moles = given mass / molar mass

moles = ???

given mass = 25 grams

molar mass = 17 grams

n = 25/17

n = 1.47 moles

Give two reasons why mixing and heating sulphur powder and iron filings on a watch glass is chemical change

Answers

Answer:

When iron filings and sulphur powder are mixed and heated they undergo a chemical reaction and form ferrous sulphide (FeS). It is a new substance which has properties entirely different from Fe and S. Therefore, heating of mixture of iron and sulphur powder is a chemical change.

URGENT:
Do you switch charges for ionic or covalent bonds when naming them?

Answers

Answer:

ionic

Explanation:

Which is true of binary ionic compounds?
Select one:
a. They consist of only two atoms.
b. They consist of atoms of only two elements.
c. They contain two different anions.
d. They have bonds that share two valence electrons.

Answers

Answer:

Its a or d if im stupid my b

Explanation:

Binary ionic compounds consist of atoms of only two atoms  and hence the term binary is given to them.

What are ionic compounds?

Ionic compounds or electrovalent compounds are  the type of compounds which are  formed between two elements when there is an exchange of electrons which takes place between  the atoms resulting in the formation of ions.

When the atom looses an electron it develops a positive charge and forms an ion called the cation while the other atom gains the electron and develops a negative charge  and forms an ion called the anion.

As the two atoms are oppositely charged they attract each other which results in the formation of a bond called the ionic bond and the compound is called ionic compound.

When the compounds consist of atoms  of only two elements the compound is called as a binary ionic compound.

Learn more about ionic compounds,here:

https://brainly.com/question/9167977

#SPJ6

Given isotope of nitrogen (N) contains 7 electrons, 7 protons and 8 neutrons. - What is the mass number - What is its atomic number

Answers

Answer:

Mass no= 16

and atomic no= 7

Explanation:

mass number is equals to number of protons + number of neutrons .

atomic number is equals to number of protons .

Explain why all glassware must be dry and the solvent anhydrous during formation and reaction of a Grignard reaction. Explain why it is advisable to not clean your glassware with acetone before a Grignard reaction. Include balanced chemical equations in your answer. (4 pts)

Answers

Answer:

The Grignard reagent will be destroyed

Explanation:

The Grignard reaction is based on a carbanion production (RMgX). If water is present in the glassware, a reaction can take place with [tex]H_2O[/tex] and the desired product will not be produced. Because an "H" would be transferred from water to the Grignard reagent. (See figure 1)

If we have acetone in the glassware we will have a similar problem. The Grignard reagent would be destroyed and the desired product will not be produced. The Grignard reagent will attack the carbon in the carbonyl group and the carbanion would disappear. (See figure 2)

[O.01]Which of these is the location where sea floor spreading occurs? abyss guyot ocean trenches mid-ocean ridges

Answers

Answer:

D. mid-ocean ridges

Explanation:

The location where seafloor spreading occurs is at mid-ocean ridges. Therefore option 4 is correct.

Mid-ocean ridges are underwater mountain ranges that extend through the Earth's oceans. They are formed by the tectonic plates diverging or moving apart from each other.

As the plates separate, magma rises from the mantle to fill the gap, creating new oceanic crust. The molten material solidifies to form new seafloor, which then moves away from the ridge in opposite directions.

Seafloor spreading is a key process in plate tectonics and the continuous renewal of the Earth's crust.

It leads to the expansion of the ocean basins and the formation of new crust, contributing to the overall movement and reshaping of the Earth's lithosphere.

Therefore, the correct answer is option 4: mid-ocean ridges.

Know more about mid-ocean ridges:

https://brainly.com/question/31194132

#SPJ2

What evidence suggests that global climate change is causing the oceans to get warmer?

Answers

Answer:

A large point of evidence in this would be the rate of increase in how fast the polar ice caps are melting and the ocean is rising as a result. As the climate is getting warmer so are the oceans and this is causing the ice caps which are in the ocean.

Explanation:

Other Questions
PlaceIs a city is in North AmericaIndiaTokyoHoustonPeruNew YorkTijuanaCanadaLet event A = The place is a city.Let event B = The place is in North America.What is P(A and B)? What is the equation of the circle shown below? Inspiring and motivating people with a mission or purpose is a ______________ for developing an organization that can learn and adapt. Multiple Choice necessary and sufficient condition necessary but not sufficient condition goal but not a necessary condition goal and a required precondition Simplify the following algebraic expression.square root of 39x^7 The diameter of a circle is 3.5 inches. What is the circumference of the circle? Find the solution of the system of equations shown on the graph. Please and thank you :) can someone please explain the skills in cornhole and how to perform them Please help quicklyyyy!Cora is two years older than three times Eli's age. Their ages add up to 98. Find their ages question: Hoy ellos ___ al cine. answers: A. voy B. vas C. van D. vamos does anybody have an answer to the question ? Use ____ references when you want different formulas to refer to the same cell. The compare_strings function is supposed to compare just the alphanumeric content of two strings, ignoring upper vs lower case and punctuation. But something is not working. Fill in the code to try to find the problems, then fix the problems.import redef compare_strings(string1, string2):#Convert both strings to lowercase#and remove leading and trailing blanksstring1 = string1.lower().strip()string2 = string2.lower().strip()#Ignore punctuationpunctuation = r"[.?!,;:-']"string1 = re.sub(punctuation, r"", string1)string2 = re.sub(punctuation, r"", string2)#DEBUG CODE GOES HEREprint(___)return string1 == string2print(compare_strings("Have a Great Day!", "Have a great day?")) # Trueprint(compare_strings("It's raining again.", "its raining, again")) # Trueprint(compare_strings("Learn to count: 1, 2, 3.", "Learn to count: one, two, three.")) # Falseprint(compare_strings("They found some body.", "They found somebody.")) # False which is another name for an orthodox view of historical event or period ? Before you start taking measurements though, well first make sure you understand the underlying concepts involved. By what method is each of the spheres charged? For the reaction C + 2H2 - CH2, how many moles of hydrogen are required to produce19.26 mol of methane, CHA?Select one:O a. 19.26O b. 38.52O c. 15.0O d. 24.7 Helppppp............ a system of linear equations is given by the tables. One of the tables is represented by the equation y= -1/3x + 7 the equation that represents the other equation y= x + the solution of the system is ( , ) [tex](5mn^3)^{3} [/tex] What class of organic product results when 1-heptyne is treated with a mixture of mercuric acetate (HgSO4) in aqueous sulfuric acid (H2O/H2SO4) A person with normal vision can focus on objects as close as a few centimeters from the eye up to objects infinitely far away. There exist, however, certain conditions under which the range of vision is not so extended. For example, a nearsighted person cannot focus on objects farther than a certain point (the far point), while a farsighted person cannot focus on objects closer than a certain point (the near point). Note that even though the presence of a near point is common to everyone, a farsighted person has a near point that is much farther from the eye than the near point of a person with normal vision.Both nearsightedness and farsightedness can be corrected with the use of glasses or contact lenses. In this case, the eye converges the light coming from the image formed by the corrective lens rather than from the object itself.Required:a. If a nearsighted person has a far point df that is 3.50 m from the eye, what is the focal length f1 of the contact lenses that the person would need to see an object at infinity clearly?b. If a farsighted person has a near point that is 0.600 m from the eye, what is the focal length f2 of the contact lenses that the person would need to be able to read a book held at 0.350 m from the person's eyes?