BIO 160 Chapter 2

Question 1

Matter

Answer 1

anything that has mass and takes up space.

Question 2

Element

Answer 2

any substance that cannot be broken down into simpler substances

Question 3

The 4 elements that make up 96% of most cells

Answer 3

Oxygen, Carbon, Hydrogen, Nitrogen

Question 4

Trace element

Answer 4

An element indispensable for life but required in extremely minute amounts.

Question 5

Molecule

Answer 5

smallest unit of most compounds

Question 6

Compound

Answer 6

a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight

Question 7

Atom

Answer 7

Smallest particle of an element

Question 8

Electron: charge and location

Answer 8

Part of the atom; negative charge outside nucleus

Question 9

Neutron: charge and location

Answer 9

Part of the atom; neutral charge in nucleus

Question 10

Proton: charge and location

Answer 10

Part of the atom: positive charge in nucleus

Question 11

Atomic number

Answer 11

the number of protons in the nucleus of an atom

Question 12

Atomic mass

Answer 12

number of protons and neutrons

Question 13

How to read the Periodic Table

Answer 13

Elements are arranged on the periodic table according to their atomic number

Question 14

Octet rule

Answer 14

States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons

Question 15

Isotope

Answer 15

are alternate mass forms of an element. It has the same number of protons and electrons but differ in their number of neutrons.

Question 16

Radioactive Isotope

Answer 16

have many uses in research and medicine. , an unstable atom in which the nucleus decays (breaks down) releasing particles and energy

Question 17

Covalent bond

Answer 17

bond formed by the sharing of electrons between atoms

Question 18

Ion

Answer 18

When an atom loses or gains electrons, charged

Question 19

Ionic bond

Answer 19

the attractive force between two ions of opposite charge;

Question 20

Polar molecule

Answer 20

molecule in which opposite ends have opposite electric charges (Water)

Question 21

Hydrogen bond

Answer 21

weak attraction between a hydrogen atom and another atom

Question 22

Chemical reaction

Answer 22

changes in the chemical composition of matter

Question 23

Drought

Answer 23

a period of abnormally dry weather that changes the environment and one of the most devastating disasters

Question 24

Properties of water

Answer 24

Cohesion; High surface tension; High heat capacity; Varying density; and Solvency

Question 25

Cohesion

Answer 25

Water molecules stick together

Question 26

High heat capacity

Answer 26

Water has a strong resistance to change in temperature

Question 27

High surface tension

Answer 27

hydrogen bonding of water causes the surface to be hard to break

Question 28

Varying density

Answer 28

Frozen water floats

Question 29

Solvency

Answer 29

Water is a common solvent for life

Question 30

Heat

Answer 30

a form of energy that is transferred by a difference in temperature

Question 31

Temperature

Answer 31

a measure of how hot or cold something is

Question 32

Biological significance of ice floating

Answer 32

Ice is less dense than water. If ice did not float, ponds, lakes, and even the oceans would freeze solid. Life in water could not survive if bodies of water froze solid.

Question 33

Solution

Answer 33

a liquid consisting of a mixture of two or more substances

Question 34

Solvent

Answer 34

the liquid portion of the solution

Question 35

Solute

Answer 35

the solid portion of the solution dissolved in solvent

Question 36

Acid

Answer 36

a chemical compound that releases H+ to a solution

Question 37

Base

Answer 37

a compound that accepts H+ and removes them from solution

Question 38

pH

Answer 38

describe the acidity of a solution. Mathematical way to indicate number of hydrogen ions in solution.

Question 39

Buffer

Answer 39

substances that resist pH change. Accept H+ ions when they are in excess and donate H+ ions when they are depleted.

Question 40

How to draw an atom?

Answer 40

Put protons and neutrons in the center as a nucleus. Then, proceed to draw circles around the nucleus and put electrons on the circles 2-8-8.

Question 41

compound

Answer 41

substances that contain two or more elements in a fixed ratio

Question 42

evaporative cooling

Answer 42

occurs when a substance evaporates, the liquid that is left behind cools down