Chapter 2 - Life's Chemical Basis

Question 0

Atomic number

Answer 0

Number of protons in the atomic nucleus; determines the element

Question 1

Atom

Answer 1

Particle that is a fundamental building block of all matter

Question 2

Charge

Answer 2

Electrical property. Opposite charges attract, and like charges repel

Question 3

Electron

Answer 3

Negatively charged subatomic particle that occupies orbitals around an atomic nucleus

Question 4

Element

Answer 4

A pure substance that consists only of atoms with the same number of protons

Question 5

Isotopes

Answer 5

Forms of an element that differ in the number of neutrons their atoms carry

Question 6

Mass number

Answer 6

Total number of protons and neutrons in the nucleus of an element’s atoms

Question 7

Neutron

Answer 7

Uncharged subatomic particle in the atomic nucleus

Question 8

Nucleus

Answer 8

Core of an atom; occupied by protons and neutrons

Question 9

Periodic table

Answer 9

Tabular arrangement of the known elements by atomic number

Question 10

Proton

Answer 10

Positively charged subatomic particle that occurs in the nucleus of all atoms

Question 11

Radioactive decay

Answer 11

Process by which atoms of a radioisotope emit energy and/or subatomic particles when their nucleus spontaneously disintegrates

Question 12

Radioisotope

Answer 12

Isotope with an unstable nucleus

Question 13

Tracer

Answer 13

A molecule labelled with a detectable substance

Question 14

Chemical bond

Answer 14

An attractive force that arises between two atoms when their electrons interact

Question 15

Compound

Answer 15

Type of molecule that has atoms of more than one element

Question 16

Electronegativity

Answer 16

Measure of the ability of an atom to pull electrons away from other atoms

Question 17

Ion

Answer 17

Charged atom

Question 18

Mixture

Answer 18

An intermingling of two or more types of molecules

Question 19

Molecule

Answer 19

Group of two or more atoms joined by chemical bonds

Question 20

Shell model

Answer 20

Model of electron distribution in an atom

Question 21

Covalent bond

Answer 21

Chemical bond in which two atoms share a pair of electrons

Question 22

Hydrogen bond

Answer 22

Attraction that forms between a covalently bonded hydrogen atom and another atom taking part in a separate covalent bond

Question 23

Ionic bond

Answer 23

Type of chemical bond in which a strong mutual attraction forms between ions of opposite charge

Question 24

Polarity

Answer 24

Any separation of charge into distinct positive and negative regions

Question 25

Cohesion

Answer 25

Tendency of molecules to resist separating from one another

Question 26

Evaporation

Answer 26

Transition of a liquid to a gas

Question 27

Hydrophilic

Answer 27

Describes a substance that dissolves easily in water

Question 28

Hydrophobic

Answer 28

Describes a substance that resists dissolving in water

Question 29

Salt

Answer 29

Compound that releases ions other than H+ and OH- when it dissolves in water

Question 30

Solute

Answer 30

A dissolved substance

Question 31

Solvent

Answer 31

Liquid that can dissolve other substances

Question 32

Temperature

Answer 32

Measure of molecular motion

Question 33

Acid

Answer 33

Substance that releases hydrogen ions in water

Question 34

Base

Answer 34

Substance that accepts hydrogen ions in water

Question 35

Buffer

Answer 35

Set of chemicals that can keep the pH of a solution stable by alternately donating and accepting ions that contribute to pH

Question 36

Concentration

Answer 36

The number of molecules or ions per unit volume of a solution

Question 37

pH

Answer 37

Measure of the number of hydrogen ions in a fluid