Chapter 2 Biology

Question 1

Atom

Answer 1

Particle that is fundamental building block of all matter

Question 2

Atomic number

Answer 2

Number of protons in the atomic nucleus; determines the element

Question 3

Charge

Answer 3

Electrical property; Opposite charges attract and and like charges repel

Question 4

Electron

Answer 4

Negatively charged subatomic particle that occupies orbitals around an atomic nucleus

Question 5

Element

Answer 5

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

Question 6

Isotopes

Answer 6

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

Question 7

Mass number

Answer 7

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

Question 8

neutron

Answer 8

Uncharged subatomic particle in the atomic nucleus

Question 9

Nucleus

Answer 9

Core of an atom; Occupied by protons and neutrons

Question 10

Periodic Table

Answer 10

Tabular arrangement of the known elements by atomic number

Question 11

Proton

Answer 11

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

Question 12

Radioactive decay

Answer 12

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

Question 13

Radioisotope

Answer 13

Isotope with an unstable nucleus

Question 14

Tracer

Answer 14

A molecule labelled with a detectable substance

Question 15

Chemical bond

Answer 15

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

Question 16

Compound

Answer 16

Type of molecule that has atoms of more than one element

Question 17

electronegativity

Answer 17

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

Question 18

Ion

Answer 18

Charged atom

Question 19

Mixture

Answer 19

An intermingling of two or more types of molecules

Question 20

Molecule

Answer 20

Groups of two or more atoms joined by chemical bonds

Question 21

Shell model

Answer 21

Models of electron distribution in an atom

Question 22

Covalent bond

Answer 22

Chemical bond in which two atoms share a pair of electrons

Question 23

Hydrogen bond

Answer 23

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

Question 24

Ionic bond

Answer 24

Type of chemical bind in which a strong mutual attraction forms between ions of opposite charges

Question 25

Polarity

Answer 25

Any separation of charge into distinct positive and negative regions

Question 26

Cohesion

Answer 26

Tendency of molecules to resist separating from one another

Question 27

Evaporation

Answer 27

Transition of a liquid to a gas

Question 28

Hydrophilic

Answer 28

discribes a substance that dissolves in water easily

Question 29

Hydrophobic

Answer 29

Describes a substance that resists dissolving in water

Question 30

Salt

Answer 30

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

Question 31

Solute

Answer 31

A dissolved substance

Question 32

Solvent

Answer 32

Liquid that can dissolve other substances

Question 33

Temperature

Answer 33

Measure of molecular motion

Question 34

Acid

Answer 34

substance that releases hydrogen ions in water

Question 35

Base

Answer 35

Substance that accepts hydrogen ions in water

Question 36

Buffer

Answer 36

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

Question 37

Concentration

Answer 37

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

Question 38

pH

Answer 38

Measure of the number of hydrogen ions in a fluid