Which of the following is the best definition of a chemical change?

A. All of these
B. The ability of something to undergo a change or reaction.
C. Something that can be observed or measured without changing the identity of the substance.
D. A change that alters the identity, or chemical composition, of a substance at the atomic level. ​

Answers

Answer 1

Answer:A

Explanation:


Related Questions

What is the element name for mg2SiO4

Answers

Magnesium silicate I hope this help

Answer:

forsterite

Explanation:

what is a chemical reaction of sulfric acid?

Answers

Sulfuric acid reacts violently with alcohol and water to release heat. It reacts with most metals, particularly when diluted with water, to form flammable hydrogen gas, which may create an explosion hazard. ... Hazardous decomposition products are as follows: sulfur dioxide, sulfur trioxide, and sulfuric acid fumes.

it acts violently with water or alcohol to release some heat, it does react to most metals, mostly when diluted with water to form flammable hydrogen gases, which may create an explosion hazard.

(i tried to make the g00gle answer less complicated) :)

Hydrogen sulfide gas is combusted with oxygen gas to produce sulfur dioxide gas and water vapour. If there is 48.4 L of oxygen available. What volume of hydrogen sulfide gas may be combusted if the pressure and temperature are held constant?

Answers

Answer:

2H2S + 3O2 → 2SO2 + 2H2O

V(O2) = 48.4 L

p = 105 kPa = 1.036 atm

T = 190 + 273 = 463 K

Ideal gas law:

pV = nRT

n = \frac{pV}{RT}n=  

RT

pV

 

R = 0.08206 L×atm/mol×K

n(O2) = \frac{1.036 \times 48.4}{0.08206 \times 463}=1.319 \; mol=  

0.08206×463

1.036×48.4

=1.319mol

According to the reaction:

n(H2S) = \frac{2}{3}  

3

2

​   n(O2) = \frac{2}{3} \times 1.319 = 0.8798 \;mol  

3

2

​ ×1.319=0.8798mol

V = \frac{nRT}{p} \\ V(H_2S) = \frac{0.8798 \times 0.08206 \times 463}{1.036}=32.26 \;LV=  

p

nRT

​ V(H  

2

​  S)=  

1.036

0.8798×0.08206×463

​  =32.26L

Answer: 32.26 L

Explanation:

Help meeeeeeeeeeeeeee ​

Answers

this is the answer hope it helps you!!

What happens to the wavelength and frequency of light as you move from red to violet?

A. Both wavelength and frequency increases.
B. Both wavelength and frequency decreases.
C. Wavelength decreases and frequency increases.
D. Wavelength increases and frequency decreases.

Answers

C….. if you need a diagram to see

The formula of alkanes contain 3 5 7 and 9 carbon atoms

Answers

Explanation:

In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single.

Which traits does the western harvest mouse have that might be adaptive for the environment where it lives?

Answers

Its tail helps it climb down the tall grasses and lets it swing from the grass like a monkey in a tree

Explanation:

Answer:

Into the adaptive Trait!

Explanation:

How do we determine the volume of an irreguler shaped object?

Answers

Answer:

You can measure the displacement when the object is placed in a certain volume of water.

Which terrestrial ecosystem is characterized by almost no rainfall, very hot days, and very cold nights?
A. Tundra
B. Temperate forest
C. Desert
D. Grassland ​

Answers

B. Temperate Forest is the answer
Answer:
B. Temperature forest

Why is carbon an element and not a compound?
A. Carbon bonds easily with oxygen, but not helium.
B. All carbon atoms have the same number of protons.
o C. All carbon atoms have the same number of neutrons.
.
D. Carbon is found in all living organisms.

Answers

Answer:

Carbon is found in all living organisms.

Answer: d

Explanation: i promise I've took the k-12 test

Someone pls help me I will make you brain

Answers

c-  i and iii

I hope this helps

Question 5
The energy produced by a generator can BEST be described as

A thermal

B chemical

C nuclear

D kinetic

E electrical

Answers

Answer:

E- Electrical

Explanation:

It converts mechanical energy to electrical energy

Answer:

D kinetic

The generator in turn converts the kinetic energy of the rotor to electrical energy.

Hope it helped


a reaction is said to be ________ if the bonds formed during the reaction are stronger than the bonds broken.

Answers

Answer:

Exothermic

Explanation:

Bond strength has everything to do with the energy associated with it. What I mean by that, is a stronger bond will require a lot higher of an energy input to break than a weaker bond.

In the same way, energy is released when a bond is made. So, the formation of a stronger bond releases more energy than the formation of a weaker bond.

So, putting the two ideas together, if the bonds formed as stronger than the bonds broken, then more energy is released than taken in, which means energy is released overall over the course of the reaction. This means that the reaction is exothermic.

If there was energy taken in overall, this would be an endothermic reaction.

Let me know if that makes sense, and hope I helped! :)

Exothermic reaction is a reaction in which the bonds formed during the reaction are stronger than the bonds broken.

When chemical reactions occur, there will always be an accompanying energy change.

In exothermic reaction the bonds formed in the products are stronger than the bonds broken in the reactants whereas in endothermic reaction the bonds broken in the reactants are stronger than the bonds formed in the products.

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Use the diagram to identify each item.

Answers

Explanation:

atomic no. is 42

chemical symbol is Mo

no. of protons is 42

atomic mass is 95.95

no. of electrons is 42

no. of electron in outer most shell is 1

no of electrons in the n 3 shell is 18

no. of neutron is 96

The element molybdenum is 42nd element in periodic table with the symbol Mo and  a mass of 96. It have 42 electrons and 42 protons.

What is Molybdenum?

Molybdenum (Mo) is a transition metal in periodic table included in the d-block. The atomic number of molybdenum is 42 which is the number of protons and electrons in it.

The atomic number of a neutral atom is equal to the number of electrons in it. For a neutral atom the number of electrons and protons are equal and thus the number of both electrons and protons in Mo is 42.

Mass number is the sum of number protons and neutrons in an atom. The mass number of Mo is 96 and number of protons is 42. Thus, the number of neutrons is 96 -42 = 54.

The outer shells of Mo are 4d and 5s containing 4 and 2 electrons respectively. Thus the number of outer electrons is 6.The level n= 3 is M shell which contains 18 electrons for Mo.

To find more about Mo, refer the link below:

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lol can some have helo me out its easy
1, 2 and 3

Answers

Answer:

1. A

2. C

3. C

Explanation:

1. there are single cell organisms

2. all others are abiotic factors

3. individual is just one, population is one species, community is all populations, ecosystem includes abiotic and biotic factors, biome is a large geographical area.

a 200 g of sugar was dissolved in 100 ml of water describe the solution

A.diluted
B.concentrated
C. sweet
D. very sweet

................... answer.........pls........

Answers

Answer:

b

Explanation:

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6. Which of the following is a binary compound?
a. CaCO3
b. CuSO4
c. H2O
d. Pb(NO3)2

Answers

Answer:

The answer to your question is c. H2O

Explanation:

a. CaCO3 ----> Calcium Carbonate is obviously not a binary compound because it contains more than two elements.

b. CuSO4 ----> CuSO4 stands for copper(II) sulfate. Sulfate is the polyatomic ion SO4 -2.

c. H2O ----> Binary molecular compounds are composed of only two elements. Examples are H2O, NO, SF6 etc.

d. Pb(NO3)2 ----> Lead(II) nitrate is an inorganic compound with the chemical formula Pb(NO3)2.

I hope this helps and have a great day!

why are some substances such as magnesium and fluoride allowed in drinking water?

Answers

Answer:Pure water does not contain fluoride, but much drinking water does contain fluoride that is deliberately added to reduce tooth decay of children who drink the water. Some drinking water supplies also contain fluoride naturally.

Explanation:

in small doses not harmful

Fluoride is a chemical that is intentionally added to drinking water in order to prevent tooth decay in children. Pure water does not naturally contain fluoride. Some sources of drinking water naturally contain fluoride as well.

Why magnesium and fluoride allowed in drinking water?

Fluoride is a chemical that is intentionally added to drinking water in order to prevent tooth decay in children. Pure water does not naturally contain fluoride. Some sources of drinking water naturally contain fluoride as well.

Compared to magnesium found in food, magnesium in water is present as hydrated ions, which are more easily absorbed. Thus, the role played by water magnesium in the prevention of magnesium insufficiency may be quite important for people who drink water with high magnesium levels.

To learn more about magnesium and fluoride refer to:

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If you were to mass the reactants before a reaction and then mass the products after the reaction what would you expect to find and why?


pls answer fast ill give brainliest!

Answers

Answer:

No change...

Explanation:

The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. For example, when wood burns, the mass of the soot, ashes, and gases equals the original mass of the charcoal and the oxygen when it first reacted. So the mass of the product equals the mass of the reactant.

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negative ions form when atoms _______ valence electrons.

Answers

Answer:

Negatively charged ions are called anions, and an anion is formed when an atom gains an electron. Thus, the atom has an extra charge of electrons,

Explanation:

so it becomes negatively charged.

Negative ions (or anions) are atoms that have gained electrons.

Electrons have a negative charge so if an atom is getting more of them, it's becoming more negative.


A car moves with a velocity of 15 m/s west for 3 seconds. Then, the
car moves with a velocity of 15 m/s east for 1 second. What is the
total displacement of the car?

Answers

Answer:

450 metre

Explanation:

VELOCITY = DISPLACEMENT /TIME TAKEN. THEREFORE THE DISPLACEMENT = 450 M.

Explanation:

3. If you drive for 3 hours at a constant speed and make it 400 miles, how fast did you go?​

Answers

Answer:

133.333333333 mph

or

214.5791999994464 kph

Explanation:

Answer:133.333333333 mph

or

214.5791999994464 kph

Explanation:

Predict the ions that form when magnesium(group IIA) and nitrogen (group VA) react:.

Answers

Answer:   Mg²⁺   &  N³⁻

Explanation:

Since Magnesium is in group 2, then it favors losing two electrons forming a cation with a charge of +2 ( Mg²⁺).

Since Nitrogen is in group VA, it favors gaining three electrons forming the anion with charge -3 (N³⁻).

2. Differentiate the types of tectonic plates.

Answers

There are three main types of plate boundaries:

Convergent boundaries: where two plates are colliding. Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. ...

Divergent boundaries – where two plates are moving apart. ...

Transform boundaries – where plates slide each other.

sorry pag mali ...

Answer:

Convergent boundaries: where two plates are colliding. Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. ...

Divergent boundaries – where two plates are moving apart. ...

Transform boundaries – where plates slide passed each other.

Explanation:

answer pls ASAP will mark the brainliest

Answers

First one……………………………….

For me that is the first :

Both the identity and the properties of a substance change.

how many protons would the element with the atomic number 10 contain

Answers

Answer:

10

Explanation:

Atomic number = No. of protons

Therefore, the number of protons of an element with an atomic number of 10, is also 10.

Calculate the percent composition by mass of each element in NaClO2.

Answers

Answer: Divide the mass of the first dissolved component by the solution mass, and then multiply the result by 100 to calculate the mass percentage. In our example, the first dissolved compound is NaCl; the mass percent is (10 g / 136 g) x 100 percent = 7.35 percent.

Explanation: its up, look

Using a lamp without a shade and a baseball, Juan turned on the lamp and placed it on one side of a darkened room. He sat on the other side of the room and held the baseball between his face and the lamp.

Based on the model, what would the final step of his model?

Answers

Answer:b

Explanation:

What describes a chemical reaction?

Answers

Answer:

A chemical reaction is a process where two different substances or elements are mixed together. They then undergo some sort of chemical change to become a different substance altogether.

Explanation:

How do the claims in drug ads impact the medical profession in 4 sentence

Answers

Answer:

But drug advertising is not all about deception. It can offer helpful information if you know what to look for. "Advertisements can offer information on drugs that may help many older men, especially those who have conditions that may be tough to treat or manage, such as diabetes and hypertension,"

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