Answer:
A small positively charged nucleus surrounded by revolving negatively charged electrons in fixed orbits
------------neutral particles in an atom
Answer:
neutrons :
Explanation:
Protons are positively charged, while electrons are negatively charged. Neutrons are electrically neutral, as the name suggests. The electric charge, noted Q , is a physical quantity.
In an experiment, 125ml of H2 is collected over water at 27C and barometric pressure of 753 torr. the vapor pressure of water at 27C is 26.74 what is the partial pressure of H2?
Answer:
Partial pressure of H₂ = 0.9556 atm
Explanation:
Given:
Barometric pressure = 753 torr
Vapor pressure of water = 26.74 torr
FInd:
Partial pressure of H₂
Computation:
Partial pressure of H₂ = Barometric pressure - Vapor pressure of water
Partial pressure of H₂ = 733 - 26.74
Partial pressure of H₂ = 726.26 torr
1 atm = 760 torr
So,
Partial pressure of H₂ = 726.26/760
Partial pressure of H₂ = 0.9556 atm
Select the correct answer.
Which of these conditions would most likely cause a decrease in the population of any species?
ОА.
increased competition for resources
improved access to mates
OC.
elimination of predators
OD
decrease in pathogens
Answer(A increased competition for resources
Hope you get it right have a nice day
Answer:
A. increased competition for resources
Explanation:
An isotope of lead can be represented by the following symbol ²⁰⁷ 82 PB. From this symbol, it can be deduced that one atom of the isotope has: A) 82 neutrons B) 82 protons C) 125 protons D) 207 protons
Answer:
B) 82 protons
Explanation:
The number of protons for an element never change. 82 Is the atomic number for Pb which is how many protons it has. An isotope means it has more neutrons.
PLEASE HELP A woman travels to Canada where milk is sold in liters. She wants to buy enough milk at the grocery store to last 5 days and she knows at home she uses 0.75 gallons per week. How many liters must she buy?
Answer:
About 2 liters
Explanation:
Since 1 gallon equals 3.785 liters, you figure out how many liters per week she uses by 3.785 x 0.75 which is 2.83875. Then divide that by 7 which is 0.405535 liters per day. Then multiply that by 5 days which is 2.027 liters in 5 days.
The reaction below was carried out in an acidic solution. Upper I minus, plus upper I upper O minus subscript 3 right arrow upper I subscript 2. Which statement is true about this equation?
Answer:
It has been balanced by using the half-reaction method.
Explanation:
I- and IO3- gives I2
We divide the reaction into two half-reactions
(2 I- >> I2 + 2e-) x5 ( oxidation : I goes from -1 to 0 )
2 IO3- + 12H+ + 10e- >> I2 + 6H2O ( reduction : I goes from +5 to 0 )
10 I- >> 5I2 + 10e-
2IO3- + 12H+ + 10e- >> I2 + 6H2O
-----------------------------------------------------
10 I- + 2IO3- + 12H+ >> 6I2 + 6H2O
To get the smallest numbers we divide by 2 :
5 I- + IO3- + 6H+ >> 3I2 + 3H2O
It has been balanced by using the half-reaction method. Hence, option B is correct.
What is a redox reaction?A chemical reaction that takes place between an oxidizing substance and a reducing substance.
We divide the reaction into two half-reactions
[tex](2 I^-[/tex] → [tex]I_2 + 2e^-)[/tex] x 5 ( oxidation : I goes from -1 to 0 )
[tex]2 IO^{3-} + 12H^+ + 10e^-[/tex] → [tex]I_2 + 6H_2O[/tex] ( reduction : I goes from +5 to 0 )
[tex]10 I^-[/tex] →[tex]5I_2 + 10e^-[/tex]
[tex]2IO^{3-} + 12H^+ + 10e^-[/tex] → [tex]I_2 + 6H_2O[/tex]
[tex]10 I^- + 2IO^{3-} + 12H^{+}[/tex]→ [tex]6I_2 + 6H_2O[/tex]
To get the smallest numbers we divide by 2 :
[tex]5 I^- + IO^{3-} + 6H^+[/tex] → [tex]3I_2 + 3H_2O[/tex]
Hence, option B is correct.
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How many atoms are in 10g of Al
Answer:
The correct answer is
Explanation:
hope this helps u!!
What percentage of the total incoming radiation to the Earth reaches the ground? 20 30 40 70
Answer: 22.5 percent of incoming solar radiation goes directly to the surface of the Earth and is absorbed.
Explanation: Transfer of radiation through a planet's atmosphere. A planet and its atmosphere, in our solar system, can radiate back to space only as much energy as it absorbs from incoming solar radiation.
Answer:
Explanation:
I have the notes
"Only about 40 percent actually reaches the surface of the earth"
"our atmosphere and clouds reflect bout 40 percent of incoming solar radiation back into outer space"
"The remaining 60 percent is responsible for warming the earth"
"About 20 percent of this radiation is absorbed directly by the atmosphere"
A platinum resistance thermometer has resistances of 160.0 when placed in a 0°C ice bath and 243.8 when immersed in a crucible containing a melting substance. What is the melting point of this substance? (Hint: First determine the resistance of the platinum resistance thermometer at room temperature, 20°C.)
Answer:
the melting point T = 125.36°C
Explanation:
Given that:
The resistance of a platinum thermometer at 0°C is [tex]R_o[/tex] = 160.0 ohms
The resistance of a platinum thermometer when immersed in a crucible containing a melting substance [tex]R_t[/tex] = 243.8 ohms
The temperature coefficient at room temperature 20°C = ∝ = 0.00392
The objective is to determine the melting point of this substance
To do that ; at 20°C, the resistance of the platinum thermometer can be calculated as follows:
[tex]R_{20} = R_o(1 + \alpha \Delta T)[/tex]
[tex]R_{20} = 160(1 + (0.00392 \times (20-0)^0C))[/tex]
[tex]R_{20} = 160(1 + (0.00392 \times (20))[/tex]
[tex]R_{20} = 160(1 + (0.0784)[/tex]
[tex]R_{20} = 160(1.0784)[/tex]
[tex]R_{20} = 172.544 \ ohms[/tex]
The resistance of the platinum thermometer at t°C , [tex]R_t[/tex] = [tex]R_{20}(1 + \alpha \Delta T)[/tex]
[tex]243.8 = 172.544(1 + 0.00392 \times (T-20)^0C}[/tex]
[tex]\dfrac{243.8}{ 172.544 }= (1 + 0.00392 \times (T-20)^0C}[/tex]
[tex]1.413 = (1 + 0.00392 \times (T-20)^0C}[/tex]
[tex]1.413-1 = 0.00392 \times (T-20)^0C}[/tex]
[tex]0.413 = 0.00392 \times (T-20)^0C}[/tex]
[tex]\dfrac{0.413 }{0.00392} = (T-20)^0C}[/tex]
105.36°C = (T - 20) °C
T = 105.36°C + 20 °C
T = 125.36°C
Magnesium unites completely and vigorously with oxygen to form magnesium oxide, which contains 60% magnesium by weight. If 1.00 gram of magnesium is sealed in a glass tube with 1.00 gram of oxygen, what will be present in the tube after the reaction has taken place
Answer:
After the reaction, there will 0.60 g of magnesium oxide and 0.25 g of oxygen gas present in the tube
Explanation:
Equation of the reaction between magnesium and oxygen is given as follows:
2Mg(s) + O₂(g) ---> 2MgO(s)
From the equation of reaction, 2 moles of magnesium reacts with i mole of oxygen gas to produce 1 mole of magnesium oxide
molar mass of magnesium is 24.0 g; molar mass of oxygen gas = 32.0 g; molar mass of magnesium oxide = 40.0 g
Therefore 24 g of magnesium reacts with 32 g of oxygen gas
I.00 g of magnesium will react with (24.0 / 32.0) * 1.00 g of oxygen = 0.75 g of oxygen gas.
Therefore, magnesium is the limiting reagent. Once it is used up, the reaction will stop and the excess oxygen will be left in the tube together with the product, magnesium oxide.
mass of excess oxygen = 1.00 - 0.75 = 0.25 g
mass of magnesium oxide formed = (24.0 / 40.0 g) * 1 = 0.60 g
Molar mass of Al(OH)3 =
Answer:
78.01 g/mol
Explanation:
To find the molar mass of Al(OH)₃, we have to look at the mass of each individual element on the periodic table.
Al - 26.98
O - 3(16.00) = 48.00
H - 3(1.01) = 3.03
Now add it all together.
26.98 + 48.00 + 3.03 = 78.01 or 78 g/mol
Hope that helps.
When the name of ions end with ide, is it true that they are all negative ions
Calculate mole fraction of ethylene
Glycol in solution
containing 20% g C2H6O2 by mass.
Answer:
Explanation:
20% of C2H6O2
since its a solution, this means that it has 20g of ethylene glycol and the rest is water.
Molar mass of C2H6O2 = (12 x 2) + (1 x 6) + (2 x 16)
= 62
mole = mass/molar mass
Moles of C2H6O2 = 20/62
= 0.322 mol
Moles of water = 80/18
= 4.444 mol
mole fraction = mol of solute / tatal mol of solution
Mole fraction of ethylene glycol = 0.322/(0.322 + 4.444)
= 0.068
Mole fraction of water = 1 - 0.068
= 0.932
which one of the following electronic configuration represents the element that forms simple ion with a charge of-3? (a)1s^2,2s^2,2p^6,3s^2,3p^1 (b)1s^2,2s^2,2p^6,3s^2,3p^3 (c)1s^2,2s^2,2p^6,3s^2,3p^6,3d^1,4s^2 (d)1s^2,2s^2,2p^6,3s^2,3p^6
Answer:
(b)
Explanation:
The 3s^2, 3p^6 orbitals form -3 charge.
This is the element phosphorous and an example of a -3 ion is in aluminium phosphide, AlP3.
The electronic configuration which represents the element forming a simple ion having with a charge of -3 is; 1s², 2s², 2p⁶, 3s², 3p³. Option B is correct.
In this electronic configuration, the element has a total of 16 electrons. To form a simple ion with a charge of -3, the element needs to gain three electrons. This is achieved by adding three extra electrons to the existing configuration.
When the element gains three electrons, the electron configuration becomes:
1s², 2s², 2p⁶, 3s², 3p⁶
This configuration represents the stable octet configuration, where the element has a complete outer shell with eight electrons. Since the charge is -3, it means the element has gained three extra electrons to achieve a stable configuration.
Therefore, the correct electronic configuration representing the element that forms a simple ion with a charge of -3 is 1s², 2s², 2p⁶, 3s², 3p³
Hence, B. is the correct option.
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help ASAPP plsplsplsplspls tyyyyy
Answer:
0.333333 cal/g-°C
Explanation:
Energy = mass x specific heat capacity x temperature change.
(E = mcΔT)
Energy = 100.0 cal
specific heat capacity c= unknown
mass m = 4.0 g
temperature change ΔT = 100 - 25 =75°
100 = 4c(75)
c = 0.333333 cal/g-°C
Based on the information that is given, which atom in the table has the highest mass?
The question is incomplete, the complete question is;
Atom Number of protons Number of electrons Number of neutrons
1 39 39 52
2 40 40 50
3 39 39 54
4 40 40 51
Based on the information that is given, which atom in the table has the highest mass?
a. 1
b. 2
c. 3
d. 4
Answer:
c
Explanation:
The relative atomic mass is given as; number of protons + number of neutrons. If we take the relative atomic mass of each of the options;
1) 39 +52 = 91
2) 40+50 = 90
3) 39 + 54 = 93
4) 40 + 51 = 91
Thus 3 has the highest mass as seen above, hence the answer given.
Define the term “Tyndall effect”. Which of the following would show Tyndall effect:- (Starch solution, sodium chloride solution, alcohol and water mixture)
Answer:
Tyndall Effect is the phenomenon of scattering of light by particles in a colloid or in a very fine suspension.
Starch solution would show Tyndall effect.
N/B: Heterogeneous mixtures show Tyndall effect.
Answer:The Tyndall effect is light scattering by particles in a colloid or in a very fine suspension. Also known as Willis–Tyndall scattering, it is similar to Rayleigh scattering, in that the intensity of the scattered light is inversely proportional to the fourth power of the wavelength, so blue light is scattered much more strongly than red light. An example in everyday life is the blue colour sometimes seen in the smoke emitted by motorcycles, in particular two-stroke machines where the burnt engine oil provides these particles.
Under the Tyndall effect, the longer wavelengths are more transmitted while the shorter wavelengths are more diffusely reflected via scattering. The Tyndall effect is seen when light-scattering particulate matter is dispersed in an otherwise light-transmitting medium, when the diameter of an individual particle is the range of roughly between 40 and 900 nm, i.e. somewhat below or near the wavelengths of visible light (400–750 nm).
It is particularly applicable to colloidal mixtures and fine suspensions; for example, the Tyndall effect is used in nephelometers to determine the size and density of particles in aerosols and other colloidal matter (see ultramicroscope and turbidimeter).
It is named after the 19th-century physicist John Tyndall.
Explanation:
What is the solute in the mixture of muddy water
Answer:
A solute is a solid which dissolves in a solvent. Muddy water contains water and soil, soil does not dissolve in water
What shape is represented by three bound groups and one lone pair around a
central atom?
A. Bent
B. Tetrahedral
C. Linear
D. Trigonal pyramidal
Answer:
D Trigonal pyramidal
Explanation went over in class:
Answer:
D. Trigonal pyramidal
Explanation:
A P E X !
a 2.000-g sample of a hydrated copper sulfate is heated and the waters of hydration are removed if that mass of the remaining salt is 1.278 g what was the percentage of water in the original hydrate
Answer:
36.1%
Explanation:
The following data were obtained from the question:
Mass of hydrated copper sulfate = 2 g
Mass of anhydrous copper sulfate = 1.278 g
Percentage of water =..?
Next, we shall determine the mass of water in the hydrated copper sulfate.
This can be obtained as follow:
Mass of hydrated copper sulfate = 2 g
Mass of anhydrous copper sulfate = 1.278 g
Mass of water =...?
Mass of water = Mass of hydrated copper sulfate – Mass of anhydrous copper sulfate
Mass of water = 2 – 1.278
Mass of water = 0.722 g
Finally, we can obtain the percentage of water in the hydrated copper sulfate as follow:
Mass of water = 0.722 g
Mass of hydrated copper sulfate = 2 g
Percentage of water =..?
Percentage of water = mass of water /mass of hydrate x 100
Percentage of water = 0.722/2 x 100
Percentage of water = 36.1%
Therefore, the percentage of water in the hydrated copper sulfate is 36.1%
what is the difference between the atom and isotope
Answer:
Atoms consist of a nucleus made of protons and neutrons orbited by electrons.
Isotopes are atoms that have same number of protons but they differ in the number of neutrons and in atomic mass.
Answer:
Isotopes are atoms that have the same numbers of protons but different numbers of neutrons. An ion is an atom that has gained or lost electrons, so it now has more or fewer electrons than it does protons. So an ion has a negative or positive charge.
Hope it helps :)
For reaction: 2 C + O2 --> 2 CO2 If 5.50 g C was reacted with enough O2, what would be the volume (in liter) of the CO2 generated at STP? (0 C and 1 atm)
Answer:
10.2 L of CO₂
Explanation:
Our reaction is:
2C + O₂ → 2CO₂
We convert the mass of C, to moles:
5.50 g / 12g/mol = 0.458 moles
Ratio is 2:2, so if 2 moles of C can produce 2 moles of CO₂ then 0.458 moles of C would produce 0.458 moles of gas.
By the Ideal Gases Law, we know that 1 mol of gas is contained in 22.4L, so:
0.458 mol . 22.4L / 1mol = 10.2 L
What is meant by 1m length
Answer:
The metre is defined as the length of the path travelled by light in a vacuum in 1/299 792 458 of a second.
Help me pls!
What is heliuim?
Answer:
it's a chemical Element
Explanation:
symbol He
atomic number 2.
Escribe verdad o falso: La clorofila capta la energía luminosa del sol. () La fotosíntesis degrada las sustancias orgánicas que nesecitas las células()
Answer:
La clorofila capta la energía luminosa del sol. (verdadero) La fotosíntesis degrada las sustancias orgánicas que nesecitas las células(falso)
Explanation:
La clorofila es la encargada de dar el pigmento de color verde en las plantas y la que transforma la energia luminica en energia quimica, es por eso que es verdadera.
La fotosintesis NO degrada las sustancias organicas, sino que transforma un sustrato inorganico en una fuente energetica organica para las plantas.
Esto se debe por que las plantas o vegetales son autonomas, es decir que se autoabastecen energeticamente sin necesidad de ingerir alimentos como en el caso de los mamiferos.
What's the valency of sulphur for NaHSO4 and why?
Explanation:
According to the periodic table, it has 6 valance electrons in its outermost shell of an atom. so, the valancy must be 2.
we usually subtract the valancy from 8 to no. of electrons if no. of electrons in its outermost shell is more than 5.
so, 8-6=2
is the valancy of sulpher here.
What are chemical changes of matter?
Answer:
Chemical Changes are also called Chemical Reactions. Chemical reactions involve combining different substances. The chemical reaction produces a new substance with new and different physical and chemical properties. Matter is never destroyed or created in chemical reactions.
Explanation:
why the filament of bulb has high melting point
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.
Which Group has different numbers of valence electrons?
A. Alkaline earth metals
B. Alkali metals
C. Transition metals
D. Halogens
Answer:
[tex]c. \: transition \: metals[/tex]Transition metals (Group C) have different numbers of valence electrons compared to the other groups mentioned. Therefore option C is correct.
Transition metals (Group 3-12) have varying numbers of valence electrons. This is because their valence electrons are located in more than one energy level or subshell.
The number of valence electrons for transition metals can range from 1 to 12, depending on the specific element within the group. The varying numbers of valence electrons in transition metals contribute to their diverse chemical properties and ability to form multiple oxidation states.
Therefore, transition metals (Group C) have different numbers of valence electrons compared to the other groups mentioned.
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If 50.0cm3of a saturated solution of KNO3at 40oC contained 5.05g of the salt. What is the solubility of the salt at 40oC? [KNO3=101].
Answer:
The solubility of KNO₃ at 40° C is 1 mol/dm³
Explanation:
The solubility of a substance is the number of moles of that substance (solute) contained in a unit volume of solvent at that particular temperature.
Now, Solubility = n/V where n = number of moles of KNO₃ and V = volume of saturated solution = 50.0 cm³ = 0.05 dm³
n = m/M where m = mass of KNO₃ = 5.05 g and M = molar mass of KNO₃ = 101 g/mol
n = 5.05 g/101 g/mol = 0.05 mol
Solubility = n/V
= 0.05 mol/0.05 dm³
= 1 mol/dm³
So, the solubility of KNO₃ at 40° C is 1 mol/dm³