Exam 2: Atoms and Molecules the Chemical Basis of Life

Explain how the number of valence electrons is related to the chemical properties of an atom. Use two specific examples in your explanation.

Sugar dissolves readily in water because it is a(n) ____ substance.

Figure 2-1 What does the accompanying figure represent?

The location and/or metabolism of a substance such as a hormone or drug can be followed in the body by labeling the substance with a(n):

Diagram and carefully label two water molecules using a ball-and-stick model. Then use this diagram to demonstrate how hydrogen bonds form between them.

It takes one calorie of heat to raise the temperature of one gram of water one degree Celsius at sea level. This is referred to as the ____ of water.

When a small amount of hydrochloric acid (HCl) is added to a solution of Na₂HPO₄, the pH of the solution does not change markedly. The pH also does not change drastically when a small amount of sodium hydroxide (NaOH) is added to this same solution. Based on these observations, the compound Na₂HPO₄ is:

Compare and contrast the formation, properties, and characteristics of covalent and ionic bonds.

A base is defined as a(n) _____ acceptor.

Water is most dense at 4 C . __________________

The representation H − O − H is known as a(n):

Which best statement describes an element?

The hydrogen bonds of water play an important role in the ability of animals to regulate their body temperature. Explain how this occurs.

The cohesiveness between water molecules is due largely to:

At what temperature is water most dense?

If the hydrogen ion concentration of ammonia is 0.00000000001 mol/L, then what is its pH value?

What is the approximate pH of ammonia?

Consider the aquatic insects pictured in the accompanying figure. Which characteristic of water molecules directly contributes to their remarkable "water walking" success?