Chapter 2: Chemical Compositions

Question 1

A molecule that loses an electron to a free radical

a. becomes more stable.
b. becomes electrically neutral.
c. becomes less reactive.
d. is permanently destroyed.
e. becomes a free radical itself

Answer 1

e. becomes a free radical itself

Question 2

Of the bonding forces between atoms and molecules, which are strongest?

a. hydrogen bonds
b. bonds between oppositely charged ionized groups
c. bonds between nearby nonpolar groups
d. covalent bonds
e. bonds between polar groups

Answer 2

d. covalent bonds

Question 3

1. Describe the electrical charge, mass, and location of the three major subatomic particles in an atom.

Answer 3

Neutron (no charge)
Electron (negative charge)
Proton (positive charge)

Question 4

Which four kinds of atoms are most abundant in the body?

Answer 4

Carbon, hydrogen, oxygen, nitrogen

Question 5

Describe the distinguishing characteristics of the three classes of essential chemical elements found in the body.

Answer 5

Mineral elements - 7 essential, most abundantly dissolved in extra+intracellular fluids
Trace elements - 13, very small quantities, important for growth and function

Question 6

Define ion and ionic bond.

Answer 6

Ions are atoms that are either positively (cation–protons>electron) or negatively charged (anion–electrons>protons).
An ionic bond forms when one atom loses electron (becomes positively charged) to another atom (becomes negatively charged). Opposite charges attract to form ionic bond.

Question 7

Describe the polar characteristics of a water molecule.

Answer 7

Water molecule contains two hydrogen atoms and one oxygen atom. Hydrogen electrons attracted to high electronegativity of oxygen nucleus, and form covalent bond. They are polar bonds since the oxygen is now slightly negative, and hydrogen slightly positive.

Question 8

What determines a molecule’s solubility or lack of solubility in water?

Answer 8

Whether or not the covalent bonds are polar or non-polar.