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3 years ago

Select the true statement:

Chemistry

1 answer:

timama [110]3 years ago

4 0

Answer:

D. Bonds are broken and new bonds are formed during chemical reactions only.

Explanation:

Physical changes do not result in the change of chemical composition or properties through the creation or destruction of bonds.

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B. What useful functions do oxidation numbers

disa [49]

Explanation:

b. What useful functions do oxidation numbers serve?

It is used to show oxidation and reduction (loss and gain of electrons)

b. How many molecules are in 1 mole of molecules?

1 mole = 6.022 * 10^23 molecules

c. What is the name given to the number of molecules in 1 mole?

Avogadro's Number of molecules

21. a. What is the molar mass of an element?

This is the mass of an element divided by the number of moles.

Molar mass = Mass / Number of moles

b. Write the molar mass rounded to two decimal places of carbon, neon, iron and uranium.

amu = Atomic Mass Unit

Carbon = 12.01 amu

Neon = 20.18 amu

Iron = 55.85 amu

Uranium = 238.03 amu

7 0

3 years ago

What does neural mapping allow

zaharov [31]

Answer:

The answer is C

Explanation:

8 0

2 years ago

What does this do to the electrons outside the nucleus in the gaseous atoms

AleksandrR [38]

Answer:

Explanation:

As you know, ionization energy is the energy needed to remove one mole of electrons from one mole of atoms in the gaseous state

energy

→

−

Right from the start, you can tell that the harder it is to remove an electron from an atom, the higher the ionization energy will be.

Now, the periodic trends for ionization energy can be describe as follows

ionization energy increases as you move from left to right across a period

ionization energy decreases as you go down a group

As you mentioned, if you compare the first ionization energies for oxygen and chlorine using these two trends, you will get conflicting results.

If you follow the way ionization energy increases across period, chlorine would have a higher ionization energy, since it's closer to the noble gases.

On the other hand, if you go by how ionziation energy decreases from top to bottom in a group, oxygen would have higher ionization energy, since it's located in period 2, as compared with period 3 for chlorine.

As it turns out, the trend for groups overpowers the trend for periods. As aresult, oxygen will have a higher ionization energy than chlorine.

This happens because the smaller oxygen atom has its outermost electrons held tighter by the nucleus. By comparison, chlorine's outermost atoms are located further away from the nucleus.

Not only that, but they are screened from the charge of the nucleus better, since they're located on the third energy level.

Oxygen's outermost electrons are screened by

electrons, while chlorine's are screened by

electrons.

All these factors will make chlorine's outermost electrons a little easier to remove, which implies a smaller ionization energy than that of oxygen.v

6 0

3 years ago

Which probably best indicates that a compound contains an ionic bond

alex41 [277]

I’m thinking

It conducts electricity when Molten.

5 0

3 years ago

A reaction progress curve has three peaks and two valleys between the peaks. This curve describes a reaction mechanism that invo

katrin [286]

Answer:
<span>A reaction progress curve has three peaks and two valleys between the peaks. This curve describes a reaction mechanism that involves <u>three elementary reactions</u>.

Explanation:
I have drawn the progress curve with three peaks and two valleys. In fact the peaks shows higher energy and valleys show lower energies. So, Let suppose we react A and B. This reaction between A and B results in the formation of C. In this reaction the energies of A and B are less, and during the progress of reaction they cross a transition state of higher energy and forms product C with lower energy which is present at lower valley. This was first reaction. Other two reactions will be followed by conversion of C to D and conversion of D into E.</span>

3 0

3 years ago

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