Ch. 2 Key Terms

Question 1

Atom

Answer 1

The smallest basic unit of matter

Question 2

Element

Answer 2

One particular type of atom, and it cannot be broken down into a simpler substance by ordinary chemical means.

Question 3

Compound

Answer 3

A substance made of atoms of different elements bonded together in a certain ratio.

Question 4

Ion

Answer 4

An atom that has gained or lost one or more electrons.

Question 5

Ionic Bond

Answer 5

Forms through the electrical force between oppositely charged ions.

Question 6

Covalent Bond

Answer 6

Forms when atoms share a pair of electrons.

Question 7

Molecule

Answer 7

Two or more atoms held together by covalent bonds.

Question 8

Hydrogen Bond

Answer 8

An attraction between a slightly positive hydrogen

atom and a slightly negative atom, often oxygen or nitrogen.

Question 9

Cohesion

Answer 9

The attraction among molecules of a substance

Question 10

Adhesion

Answer 10

The attraction among molecules of different substances.

Question 11

Solution

Answer 11

A mixture of substances that is the same through-out—it is a homogeneous mixture.

Question 12

Solvent

Answer 12

The substance that is present in the greater amount and that dissolves another substance.

Question 13

Solute

Answer 13

A substance that dissolves in a solvent.

Question 14

Acid

Answer 14

A compound that releases a proton—a hydrogen ion (H+)—when it dissolves in water.

Question 15

Base

Answer 15

Compounds that remove H+ ions from a solution.

Question 16

pH

Answer 16

A solution’s acidity, or H+ ion concentration, is measured by the pH scale.

Question 17

Monomer

Answer 17

Each subunit in the complete molecule.

Question 18

Polymer

Answer 18

A large molecule, or macromolecule, made of many monomers bonded together.

Question 19

Carbohydrid

Answer 19

Molecules composed of carbon, hydrogen, and oxygen, and they include sugars and starches.

Question 20

Lipid

Answer 20

Non-polar molecules that include fats, oils, and cholesterol.