Chapter 2: The Chemical Context of Life

Question 1

Negatively charged ion

Answer 1

Anion

Question 2

Smallest unit of life

Answer 2

Atom

Question 3

Total mass of an atom, accounting for their isotopes

Answer 3

Atomic Mass

Question 4

The number of protons in the nucleus of an atom, unique for each element and designated by a subscript

Answer 4

Atomic Number

Question 5

An atoms dense central core, containing protons and neutrons

Answer 5

Atomic Nucleus

Question 6

Positively charged ion

Answer 6

Cation

Question 7

Attraction between 2 atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. Bonded atoms gain a complete outer valence shell with full
8 electrons.

Answer 7

Chemical Bond

Question 8

In chemical reaction, the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of reactants and products do not change with time

Answer 8

Chemical Equilibrium

Question 9

Making and breaking of chemical bonds, leading to charges in the composition of matter

Answer 9

Chemical Reaction

Question 10

Substance consisting of two or more different elements combined in a fixed ratio

Answer 10

Compound

Question 11

Strong chemical bond in which 2 atoms share one or more pairs of valence electrons

Answer 11

Covalent Bond

Question 12

Double covalent bond; the sharing of two pairs of valence electrons by two atoms

Answer 12

Double Bond

Question 13

Type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity

Answer 13

Electron

Question 14

Attraction of a given atom for the electrons of a covalent bond

Answer 14

Electronegativity

Question 15

An energy level of electrons at a characteristic average distance from the nucleus of an atom

Answer 15

Electron Shell

Question 16

Any substance that can not be broken down to any other substance by chemical reactions

Answer 16

Element

Question 17

The capacity to cause change, especially to do work

Answer 17

Energy

Question 18

Chemical element required for an organism to survive, grow, and reproduce

Answer 18

Essential Element

Question 19

Weak chemical bond that is formed when the slightly positive hydrogen atom if a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule

Answer 19

Hydrogen Bond

Question 20

An atom or group of atoms that has gained or lost one or more electrons; thus acquiring a charge

Answer 20

Ion

Question 21

A chemical bond resulting from the attraction between opposite charged ions (anions/cations)

Answer 21

Ionic Bond

Question 22

Compound resulting from the formation of an ionic bond; also called salts

Answer 22

Ionic Compound

Question 23

One of several atomic forms of an element, each with the same number of protons but different number of neutrons. Changing its atomic mass

Answer 23

Isotope

Question 24

Total number of protons and neutrons in an atom’s nucleus

Answer 24

Mass Number

Question 25

Anything that takes up space and has mass

Answer 25

Matter

Question 26

Two or more atoms held together by covalent bonds

Answer 26

Molecule

Question 27

Type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity

Answer 27

Nonpolar Covalent Bond

Question 28

Subatomic particle having no electrical charge

Answer 28

Neutron

Question 29

3D space where an electron is found 90% of the time

Answer 29

Orbital

Question 30

Covalent bond between atoms that differs in electronegativity. The electrons are pulled closer to the more electronegative atom, making it slightly more negative and the other more positive

Answer 30

Polar Covalent Bond

Answer 31

Potential Energy

Question 32

A material resulting from the chemical reaction

Answer 32

Product

Question 33

Subatomic particle with single positive electrical charge

Answer 33

Proton

Question 34

An isotope that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy

Answer 34

Radioactive Isotope

Question 35

Starting materials in the chemical reaction

Answer 35

Reactant

Question 36

Compound resulting from the formation of an ionic bond; also called an ionic compound

Answer 36

Salt

Question 37

Single covalent bond; the sharing of a pair of valence electrons by two atoms

Answer 37

Single Bond

Question 38

An element indispensable for life but required in extremely minute amounts

Answer 38

Trace Element

Question 39

Bonding capacity of a given atom, the number of covalent bonds an atom can form, which usually equals the number of electrons in its outermost shell

Answer 39

Valence

Question 40

An electron in the outermost electron shell

Answer 40

Valence Electron

Question 41

The outermost energy shell of an atom, containing the electrons involved in the chemical reactions of that atom

Answer 41

Valence Shell

Question 42

Weak attractions between molecules or parts of molecules that result from transient local partial charges

Answer 42

Van Der Waals Interactions