chapter 2

Nitrogen has an atomic number of seven. How many electron shells does it likely have?

b. two

C6H12O6 is the chemical formula for a ________.

c. hexose monosaccharide

Which of the following statements about chemical bonds is true?

a. Covalent bonds are stronger than ionic bonds.

When an atom donates an electron to another atom, it becomes

a. an ion

Uracil ________.

a. contains nitrogen b. is a pyrimidine c. is found in RNA d. all of the above*

What organic compound do brain cells primarily rely on for fuel?

a. glucose

A phospholipid ________.

a. has both polar and nonpolar regions

Which of the following combinations of atoms is most likely to result in a chemical reaction?

a. hydrogen and hydrogen

The energy stored in a foot of snow on a steep roof is

a. potential energy

The characteristic that gives an element its distinctive properties is its number of

a. protons

Which of the following is most likely to be found evenly distributed in water in a homogeneous solution?

a. sodium ions and chloride ions

The smallest unit of an element that still retains the distinctive behavior of that element is an _

atom

Ty is three years old and as a result of a "stomach bug" has been vomiting for about 24 hours. His blood pH is 7.48. What does this mean?

b. Ty's blood is slightly alkaline.

A pentose sugar is a part of the monomer used to build which type of macromolecule?

b. nucleic acids

CH4 is methane. This compound is ________.

b. organic

A substance formed of crystals of equal numbers of cations and anions held together by ionic bonds is called a(n

b. salt

The ability of an enzyme's active sites to bind only substrates of compatible shape and charge is known as

b. specificity

The bonding of calcium, phosphorus, and other elements produces mineral crystals that are found in bone. This is an example of a(n) ________ reaction.

b. synthesis

Which of the following is a molecule, but not a compound?

c. H2

Which of the following is a functional group that is part of a building block of proteins?

c. amino

AB→A+B is a general notation for a(n) ________ reaction.

c. decomposition

On the periodic table of the elements, mercury (Hg) has an atomic number of 80 and a mass number of 200.59. It has seven stable isotopes. The most abundant of these probably have ________.

c. more than 80 neutrons each

A molecule of ammonia contains one atom of nitrogen and three atoms of hydrogen. These are linked with

c. polar covalent bonds

A substance dissociates into K+ and Cl- in solution. The substance is a(n) ________.

c. salt

________ reactions release energy.

d. Catabolic, exergonic, and decomposition

In DNA, nucleotide bonding forms a compound with a characteristic shape known as a(n) ________.

d. double helix

Together, just four elements make up more than 95 percent of the body's mass. These include ________.

d. oxygen, carbon, hydrogen, and nitrogen

Chewing a bite of bread mixes it with saliva and facilitates its chemical breakdown. This is most likely due to the fact that ________.

d. saliva contains enzymes

Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. The chocolate-chip batter is an example of a ________.

d. suspension