Question 1

Which of the following statements best describes the relationship between matter, chemical elements, and atoms?

Accepted Answer

Matter is composed of chemical elements, which are made of atoms.

Question 2

Which subatomic particle is responsible for the atomic number of an element?

Accepted Answer

Proton

Question 3

A neutral atom of carbon has 6 protons and 6 neutrons. What is its mass number?

Accepted Answer

$$12$$

Question 4

Which of the following best explains why neon (Ne) is chemically unreactive?

Accepted Answer

Its valence shell is full with 8 electrons.

Question 5

How many neutrons are present in an oxygen atom with atomic number 8 and mass number 16?

Accepted Answer

$$8$$

Question 6

Which of the following is true about electron energy shells?

Accepted Answer

They represent regions around the nucleus in which the electrons orbit.

Question 7

According to the octet rule, how many electrons does an oxygen atom need to gain to fill its valence shell?

Accepted Answer

$$2$$

Question 8

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 9

Radioactive isotopes are used in all of the following EXCEPT:

Accepted Answer

Increasing the stability of atoms in living organisms.

Question 10

How many years must pass for a sample of Carbon-14 to decay to $$\frac{1}{4} of $$its original amount, given its half-life is 5,730 years?

Accepted Answer

$$11,460$$ years

Question 11

Which of the following best describes a covalent bond?

Accepted Answer

An interaction between two atoms resulting from the sharing of electrons.

Question 12

What makes a covalent bond nonpolar?

Accepted Answer

The bonded atoms share electrons equally and have similar electronegativities.

Question 13

Which of the following is a property of polar covalent bonds?

Accepted Answer

One atom has a partial negative charge.

Question 14

Which of the following is a weak non-covalent chemical bond important in biological systems?

Accepted Answer

Hydrogen bond

Question 15

When an atom gains an electron, it becomes:

Accepted Answer

A negatively charged anion

Question 16

Which of the following best describes an ionic bond?

Accepted Answer

Atoms of opposite charges attract each other.

Question 17

Which of the following is most likely to lose an electron and become a cation with a +1 charge?

Accepted Answer

An atom with one valence electron

Question 18

What property of the bond between a hydrogen atom and an oxygen atom in a water molecule makes it a polar bond?

Accepted Answer

Oxygen is more electronegative than hydrogen.

Question 19

Which of the following best explains why water molecules are attracted to each other?

Accepted Answer

Hydrogen bonds form between the partial positive charge of hydrogen and the partial negative charge of oxygen.

Atoms, Elements, and Chemical Bonding: General Chemistry Study Notes

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