Answer:
The filament of a bulb has a high melting point because of the heat generated inside the bulb.
Explanation:
When electricity is concentrating and run through a bulb, it starts to generate heat. Leave it on long enough and it will start to build up a lot of heat. Have you ever tried touching a light bulb when it has been all day? It's scorching to the skin.
Since electricity generates heat, the bulb's filament has to have a high melting point so it doesn't melt, destroy the bulb, and leave you light-less. If the filament has a high melting point, then it is able to withstand heat generated by electricity and provide you light.
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
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.
URGENT:
Do you switch charges for ionic or covalent bonds when naming them?
Answer:
ionic
Explanation:
Give two reasons why mixing and heating sulphur powder and iron filings on a watch glass is chemical change
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.
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]
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.
What is the unit charge on each subatomic particles
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:
please help !!!
How much of KCIO3, must be heated to produce as much O2, as required to burn 24 g of carbon?
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:
what is a chemical bond? an attractive force between 2 molecules
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)
What evidence suggests that global climate change is causing the oceans to get warmer?
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:
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.
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.
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) What mass of potassium nitrate would be needed to
produce a saturated solution of potassium nitrate in
50 grams of water at 313 K?
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
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
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! : )
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
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.
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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.
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
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)
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.
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
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)
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)
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.
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:
If a had a number that was 12.47, what would be the answer rounded to 2 sig figs?
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.
Given isotope of nitrogen (N) contains 7 electrons, 7 protons and 8 neutrons. - What is the mass number - What is its atomic number
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 .
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
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.
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[O.01]Which of these is the location where sea floor spreading occurs? abyss guyot ocean trenches mid-ocean ridges
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.
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Which of the following will only affect the reaction rate of gases?
A. Concentration
B. Catalyst
C. Pressure
D. Surface area
Answer:
D. Pressure
Explanation:
The rate of a reaction is defined as the speed at which the reactants are converted into products. Factors influencing the rate of a reaction are concentration, catalyst, temperature, surface area, and pressure, etc.
In case of the reaction rate of gases, pressure will only have its affect as pressure do not have any influence on solid and liquid.
While concentration, surface area and catalyst influence all reaction rates including solid, liquids and gases.
Hence, the correct option is (d) pressure.
example of nobel gas
Answer:
helium , krypton,xenon,radon, argon are noble gasses
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
Answer:
The answer is option BExplanation:
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...
Which two features of Earth's crust involve tension?
O A. Convergent boundaries
B. Reverse faults
c. Divergent boundaries
O D. Normal faults
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:
How many moles is 25g of ammonia (NH3) pls show steps and answere asap
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
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
Describe how red shifts were used by cosmologists to determine that the universe was expanding. How
is this evidence for the big bang theory?
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 .
Adding a base to a solution would...?
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.
Which action destroys topsoil?
Answer:
I think it erosion
Explanation:
Well erosion washes away top soil