Atomic mass = $$n(\text{protons}) + n(\text{neutrons})$$

Question 1

Which subatomic particle is responsible for the atomic number of an element, and what is its charge?

Accepted Answer

Proton; positive charge

Question 2

If an atom has 6 protons, 6 neutrons, and 6 electrons, what is its atomic mass and atomic number?

Accepted Answer

Atomic mass = $$12$$, Atomic number = $$6$$

Question 3

Which of the following best describes the difference between an atom and an element?

Accepted Answer

An atom is the smallest unit of matter with unique chemical properties; an element is a substance made of only one kind of atom.

Question 4

Which four elements make up the majority of the human body by mass?

Accepted Answer

Oxygen, Carbon, Hydrogen, Nitrogen

Question 5

A radioactive isotope of iodine is used to treat thyroid disorders. What property makes it suitable for this medical application?

Accepted Answer

It emits high-energy radiation as its nucleus decays, which can destroy overactive or cancerous thyroid tissue.

Question 6

Which statement correctly distinguishes between isotopes and radioisotopes?

Accepted Answer

Isotopes differ only in the number of neutrons; radioisotopes are unstable isotopes that undergo radioactive decay.

Question 7

A solution is made by dissolving salt in water. In this example, which is the solvent and which is the solute?

Accepted Answer

Water is the solvent; salt is the solute.

Question 8

Which of the following best describes a colloid?

Accepted Answer

A mixture with small, evenly distributed particles that do not settle out and scatter light.

Question 9

Which rule explains why atoms with 8 electrons in their valence shell are chemically stable?

Accepted Answer

Octet Rule

Question 10

An atom with 1 valence electron reacts with an atom with 7 valence electrons. What type of bond is most likely to form between them?

Accepted Answer

Ionic bond

Question 11

Which of the following is true about ions and electrolytes?

Accepted Answer

Electrolytes are substances that ionize in water and can conduct electricity.

Question 12

Which type of chemical bond is responsible for the unique properties of water, such as its high boiling point and surface tension?

Accepted Answer

Hydrogen bonds

Question 13

A molecule of oxygen ($$O_2) is $$held together by which type of bond?

Accepted Answer

Non-polar covalent bond

Question 14

Which of the following best explains why sodium chloride ($$NaCl) $$dissolves easily in water?

Accepted Answer

Water's polarity allows it to surround and separate the positive sodium and negative chloride ions.

Question 15

Which of the following is a correct formula for calculating atomic mass?

Accepted Answer

Atomic mass = $$n(	ext{protons}) + n(	ext{neutrons})$$

Question 16

Which scenario best illustrates the formation of a polar covalent bond?

Accepted Answer

Two atoms share electrons unequally, creating partial positive and negative poles.

Question 17

Which of the following is a biological example of a hydrogen bond?

Accepted Answer

The attraction between water molecules in liquid water

Question 18

A patient receives a diagnostic scan using gallium-67. What property of gallium-67 is most important for this procedure?

Accepted Answer

It emits detectable radiation as it decays, allowing imaging of organs and tissues.

Question 19

Which of the following best describes Van der Waals forces?

Accepted Answer

Weak attractions between nonpolar molecules due to temporary polarization

Matter, Energy & Bonds: Foundations for Anatomy & Physiology

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