Chapter 2-Life's Chemical Basis

Question 1

A pure substance consisting of atoms with the same number of protons

Answer 1

Element

Question 2

A group of two or more atoms joined by chemical bonds

Answer 2

Molecule

Question 3

Defines all elements by the number of protons in the atomic nucleus

Answer 3

Atomic number

Question 4

The periodic table lists elements in order of their ___________.

Answer 4

Atomic number

Question 5

An atom’s ______\__________ is the total number of protons plus neutrons in the atomic nucleus.

Answer 5

Mass number

Question 6

_____________ can be used to identify different forms of the same element. (i.e. Isotopes)

Answer 6

Atomic mass

Question 7

The number of protons/electrons/neutrons of an atom of a given element CAN change, but the number of protons/electrons/neutrons CAN’T change. (May choose more than 1)

Answer 7

Neutrons & electrons

Protons

Question 8

Forms of an element that differ in the number of neutrons their atoms carry (have same atomic #, but different atomic masses)

Answer 8

Isotopes

Question 9

Isotopes with an unstable nucleus

Answer 9

Radioisotopes

Question 10

Energy and/or subatomic particles emitted as an unstable nucleus spontaneously breaks up

Answer 10

Radioactive decay

Question 11

Detectable substances (not just isotopes) that researchers use to track biological/ geological processes.

Answer 11

Tracers

Question 12

Help to visualize how electrons arranged around atoms, from the innermost orbital (or she’ll) outward

Answer 12

Shell model

Question 13

Volumes of space around an atom’s nucleus

Answer 13

Orbitals

Question 14

When an atom’s outermost she’ll has room for additional electrons (i.e., has vacancies) it is typically _____________.

Answer 14

Chemically active

Question 15

Solitary atoms that have unpaired electrons in the outermost shell are called–

Answer 15

Free radicals

Question 16

Attractive force that unites two atoms as a molecule when their electrons interact

Answer 16

Chemical bond

Question 17

Molecule that is composed of atoms from more than one element, the proportions of which are constant. (Ex: glucose is always C6H12O6)

Answer 17

Compound

Question 18

What are the 3 types of chemical bonds?

Answer 18

Covalent bonds (strongest)
Ionic bonds
Hydrogen bonds (weakest)

Question 19

Forms when two atoms share a pair of electrons

Answer 19

Covalent bond

Question 20

Forms when atoms share electrons unequally (ex: water)

Answer 20

Polar covalent bond

Question 21

Atoms with an unequal number of protons and electrons

Answer 21

Ions

Question 22

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

Answer 22

Electronegativity

Question 23

Atoms that have Gained electrons are called ______ _____. Atoms that have lost electrons are called _____ _____.

Answer 23

Negative ions

Positive ions

Question 24

Strong mutual attraction that links ions of opposite charge

Answer 24

Ionic bond

Question 25

The separation of charge into positive and negative regions

Answer 25

Polarity

Question 26

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

Answer 26

Hydrogen bond

Question 27

Polar/Non-Polar molecules have a slight charge associated with part of the molecule, which allows hydrogen bonding even though the overall charge is neutral Polar/Non-Polar molecules have no charge and cannot form hydrogen bonds

Answer 27

Polar | Non-Polar

Question 28

Extensive _______ bonding among water molecules gives liquid water several special properties that make life possible

Answer 28

Hydrogen

Question 29

What are the 3 characteristics of water as a result of hydrogen bonding?

Answer 29

1. Excellent solvent 2. cohesive 3. Resists temperature change

Question 30

_________ substances resist dissolving in water

Answer 30

Hydrophobic

Question 31

The tendency for molecules to resist separating from one another because hydrogen bonds collectively exert a continuous pull on individual molecules

Answer 31

Cohesion

Question 32

A measure of the concentration of hydrogen ions in a liquid

Answer 32

pH

Question 33

The higher/lower the concentration of H+ ions, the higher/lower the pH

Answer 33

Higher | Lower

Question 34

Substance that releases hydrogen ions in a solution

Answer 34

Acid

Question 35

Substance that accepts hydrogen ions or releases hydroxide ions

Answer 35

Base