An electrically neutral atom consists of 15 neutrons,13 electrons, and a number of protons.what is its mass number
Answer:
28
Explanation:
The atom is neutral, which means the quantity of electrons and protons square measure an equivalent. thus if there square measure 13 electrons, there square measure 13 protons. and therefore the nucleon number is neutrons and protons. thus 13+15 is 28
Which of these metals is the least reactive?
in
caldum
sodium
potassium
Answer:
Calcium
Explanation:
It is because sodium and potassium are highly reactive metal i.e. Group 1 but calcium is Group 2 element. So, calcium is least reactive.
A sample of gas has a volume of 20.0 mL at STP. What will the volume be if the temperature is changed to 546 K and the pressure is changed to 2.0 atm.? (show work plz)
The volume did not change, it remained at 20 ml
Further explanationGiven
20 ml a sample gas at STP(273 K, 1 atm)
T₂=546 K
P₂=2 atm
Required
The volume
Solution
Combined gas Law :
[tex]\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}[/tex]
Input the value :
[tex]\tt \dfrac{1\times 20}{273}=\dfrac{2\times V_2}{546}\\\\V_2=\dfrac{1\times 20\times 546}{273\times 2}\\\\V_2=20~ml[/tex]
The volume does not change because the pressure and temperature are increased by the same ratio as the initial conditions (to 2x)
Synthesis
Decompisition
O Combustion
O Single Displacement
O Double Displacement
Answer:
Synthesis
Explanation:
Nothing else works
Do your answers to the previous questions satisfy
the following statements?
A) The dependent variable is changed by the
independent variable.
B) The independent variable causes a change
to another variable.
C) The independent variable is not changed by
another variable.
Answer:
I put B&C
Explanation:
can someone please help me solve this? i dont understand this problem :(
Answer:
–4020 KJ
Explanation:
The following data were obtained from the question:
H₂(g) + F₂(g) —> 2HF(g) ΔH = –536 KJ
Next, we shall determine the mass of H₂ that reacted from the balanced equation to produce –536 KJ of heat energy. This can be obtained as follow:
Molar mass of H₂ = 2 × 1 = 2 g/mol
Mass of H₂ from the balanced equation = 1 × 2 = 2 g.
Summary:
From the balanced equation above,
2 g of H₂ reacted to produce –536 KJ of heat energy.
Finally, we shall determine the heat change produced by the reaction of 15 g of H₂. This can be obtained as follow:
From the balanced equation above,
2 g of H₂ reacted to produce –536 KJ of heat energy.
Therefore, 15 g of H₂ will react to produce = (15 × –536)/2 = –4020 KJ of heat energy.
Thus, the heat change for the reaction is –4020 KJ
(60 points + brain list)
Which is the configuration of an atom in the ground state?
A)
2-8-2
B)
2-6-1
C)
2-7-2
D)
2-7-3
Answer:
Ground state means when n = 1
and here the electronic configuration is 2:8:2
PLEASE HELP When I combine Sprite with a sour candy, it starts to bubble a lot. Is this a physical or chemical change?
A. Physical Change
B. Chemical Change
Answer:
B. chemical
Explanation:
Chemical change cannot go back to its original form
Answer:
B
Explanation:
bubbles is a form of chemical change :)
What is the volume of a balloon that contains a 1.00 mol sample of oxygen with a pressure of 2.00 atm at 300.0 K?
Answer:
12.3
Explanation:
Trust
Ideal gas law is valid only for ideal gas not for vanderwaal gas. Therefore, 12.3L is the volume of a balloon that contains a 1.00 mol sample of oxygen with a pressure of 2.00 atm at 300.0 K.
What is ideal gas equation?Ideal gas equation is the mathematical expression that relates pressure volume and temperature. There is no force of attraction between the particles.
Mathematically the relation between Pressure, volume and temperature can be given as
PV=nRT
where,
P = pressure of oxygen gas= 2.00 atm
V= volume of oxygen gas =?
n =number of moles of oxygen gas=1.00 mol
T =temperature of oxygen gas =300.0 K
R = Gas constant = 0.0821 L.atm/K.mol
Substituting all the given values, we get
2.00×V=1× 0.0821×300.0
On calculation we get
Volume=12.3L
Therefore, the volume of oxygen is 12.3L.
To learn more about ideal gas equation, here:
https://brainly.com/question/14826347
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How many molecules are found in 60 grams of KOH?
Explain step by step please
Answer:
6.624× 10²³ molecules
Explanation:
Given data:
Mass of KOH = 60 g
Number of molecules = ?
Solution:
First of all we will calculate the number of moles.
Number of moles = mass/molar mass
Number of moles = 60 g/ 56.1 g/mol
Number of moles = 1.1 mol
Now number of molecules are determine by using Avogadro number.
1 mole = 6.022 × 10²³ molecules
1.1 mol × 6.022 × 10²³ molecules / 1mol
6.624× 10²³ molecules
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
A student mixes 20.0g of white KCl crystals with distilled water in a beaker. After the mixture was stirred, no crystals are visible and the solution is clear. After several days, all of the water evaporates and white crystals are found in the beaker. Which of following pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred?
Answer:
After the water has evaporated, the white crystals in the beaker have a mass of 20.0g.
The pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred is of 20.0 g of white KCl crystals.
What are physical changes?Physical changes are defined as a modification to a sample of material when some of the substance's attributes change but the composition of the sample remains the same. The digestion of food, combustion, osmosis, and phase transitions are just a few examples of how these changes play a crucial role in our daily lives.
Crystals are defined as a solid substance whose elements such as atoms, molecules, or ions are grouped in a highly organized microscopic structure to create an all-pervasive crystal lattice. Crystals are formed when molecules in a liquid group together to stabilize when it starts to cool and solidify.
Thus, the pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred is of 20.0 g of white KCl crystals.
To learn more about physical change, refer to the link below:
https://brainly.com/question/17931044
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Select the correct answer from each drop-down menu.
Researchers stationed at different areas on a mountain and in a tunnel midway through the mountain boiled water at the same time. Even though the water at every station was at the same temperature, the pot at the top of the mountain started boiling before the others. Why?
Water boils when the vapor pressure is
the atmospheric pressure. The atmospheric pressure
at the top of the mountain.
Water boils when the vapour pressure is least the atmospheric pressure.
The atmospheric pressure is equal at the top of the mountain.
What is atmospheric pressure?The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth.
As we go up in altitude the air pressure becomes less. When the pressure decreases, it takes less energy to get the water molecules to escape the surface. So the temperature is less than it would be at sea level.
Air pressure is higher or greater at the bottom of a mountain. This is because the height of the air above that level is thicker than at the top.
Pressure is given by the equation, P=rho*g*h, where rho is the air density, g is the gravity value and h is the thickness of the air layer on top of the level where we are considering the pressure.
Therefore, as we can see, at the bottom of the mountain, the thickness h of air is greater, and so is the pressure.
Hence, water boils when the vapour pressure is least the atmospheric pressure and the atmospheric pressure is equal at the top of the mountain.
Learn more about the atmospheric pressure here:
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Attempt 1
Question
You see Fred, a co-worker, not following safety procedures. What would be the best
thing to do?
A) nothing, as his safety is his own responsibility
B) pretend you didn't see him, but consider telling the boss
C) talk to him about putting his safety at risk
D) follow his example -- maybe the safety procedures are not necessary
Answer:
Would be C
Explanation:
helpig and bringing noice to a persons safety is always the right thing. C is correct, hope this helps
Although the order of elements is based on atomic number, vertical families share similar chemical properties.
Question 12 options:
True
False WHAT IS IT
Answer:
It's true
Explanation:
Uhhh, the internet! lol.
Answer:
It's true, ExplanationVVVExplanation: Because the order of elements is based on atomic number, vertical families share similar chemical properties.
The electron configuration of an element is 1522s22p63523p6451. Why is this a REPRESENTATIVE element?
A)
All orbitals are completely filled.
B)
The outermost electron is a valence electron.
The outermost electron is added to the p-orbital.
D
The highest s-orbital or p-orbital is partially filled.
Describe the subatomic particles found in an atom, and
describe each one. Also, describe how they relate to each
other.
pls helpp <3
Please actually help me.
Thank you!
Answer: I believe -3
Explanation:
determine the theoretical yield.
aluminum metal reacts with aqueous nickel II sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. in this reaction 108 grams of aluminum were combined with 464 grams of nickel II sulfate to produce 274 grams of aluminum sulfate.
The question is incomplete, the complete question is;
In this stoichiometry problem, determine the percentage yield:
Excess aluminum metal reacts with aqueous nickel(II) sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. In this reaction 108 g of aluminum were combined with 464 g of nickel(II) sulfate to produce 274 g of aluminum sulfate.
Answer:
80%
Explanation:
The correct equation for this reaction is;
2Al(s) + 3NiSO4(aq) --------> Al2(SO4)3 + 3Ni(s)
We already know that Al is in excess then NiSO4 is the limiting reactant.
Hence, Number of moles in 464 g of NiSO4 = mass/ molar mass
Molar mass of NiSO4 = 155 g/mol
Number of moles = 464g/155g/mol = 2.99 moles
Number of moles of Al2(SO4)3 = mass/molar mass
molar mass = 342 g/mol
So, Number of moles = 274g/342g/mol = 0.8 moles
Given the stoichiometric reaction equation;
3 moles of NiSO4 yields 1 mole of Al2(SO4)3
2.99 moles of NiSO4 yields 2.99 * 1/3 = 1 mole of Al2(SO4)3
percentage yield is given by; actual yield/ theoretical yield * 100/1
actual yield = 0.8 moles of Al2(SO4)3
Theoretical yield = 1 mole of Al2(SO4)3
Hence;
% yield = 0.8/1 * 100 = 80%
do pressure and temputer remain consant in earth interior
Answer:
no
Explanation:
which rock is the result of changes on the Earth's surface?
igneous rock
sedimentary rock
metamorphic rock
Answer:
metamorphic
Explanation:
when one rock changes another rock the rock that got changed is now metamorphic
how deficiency and excess of chromium
Answer:
The chromium found in foods will not hurt you. But taking excessive chromium supplements can lead to stomach problems and low blood sugar (hypoglycemia). Too much chromium from supplements can also damage the liver, kidneys, and nerves, and it may cause irregular heart rhythm.
how many moles of silicon are in 5.9 X 10 to the 24 power atoms of silicon
Answer:
9.79740949850 moles
Explanation:
1 mole = Avogardo's Number <<6.022 E 23 <<particles, atoms, etc.>>This problem can be solved using dimensional analysis by multiplying atoms (5.9E24 atoms) by (1) mole and then dividing the number by Avogardo's number (6.022 E 23 atoms).Note: E = * 10Side Note: Please let me know if you need any clarifications about this!
When do you identify your variables?
After the results
After the conclusion
Before the hypothesis
Before the question
Answer:
Before the hypothesis
Explanation:
Explain in a short sentence how you can tell if a reaction is a combustion reaction.
The reactants react with oxygen and there is energy formed.
What is the definition of hydro energy
Answer:
a form of energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity.
Explanation
Explain how the need for energy is the driving force of the oxygen cycle.
Yet again earth science
Answer:
Engery is the driving force of the oxygen cycle is photosynthesis itself, which is responsible for the creation and maintenance of earth's atmosphere.Plants are able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates and oxygen.
Answer:
Energy is the main force of the oxygen cycle and not to mention also photosynthesis, which is responsible for the creation of the earth's atmosphere. This would also mean that plants are the main focus of the Oxygen cycle and energy is needed to make plants. So without energy, no plants would exist! Not to mention the oxygen cycle wouldn't work without energy. Plants are also able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates and oxygen.
Hope this helps! :)
Explanation:
8. __H2 + __O2-> __H2O
9. __K2SO4 + __H2-> __H2SO4 + __K
10. __NO2 + __H2O-> __HNO3 + __NO
Anser:
Explanation:
hope this helps
which one of the following groups are decomposers a. algae b. protist c. fungi d. green plants e. photosynthetic bacteria?
Answer:
c. fungi
Explanation:
Decomposers are organisms that breaks down dead and decaying matter in nature. They derived their nourishment by breaking down other complex organic matter.
Fungi are a group of organisms that are mainly decomposers.
They recyclers in nature.
Green plants and photosynthetic bacteria are similar in that they obtain nourishment by the use of light to initiate the reaction between carbon dioxide and water.
Many protists are decomposers but not all.
Which statement describes a physical property to the particles that make up a material
Answer:
Gold is a relatively dense metal because its atoms have more
protons than atoms of many other metals.
Explanation:
name a lustrous non- metal ?
Answer:
it is iodine it seems very right