Chemistry Review

Question 1

positive charge, mass of 1 AMU, in nucleus, decides identity (element) of atom

Answer 1

proton

Question 2

no charge, mass of 1 AMU, in nucleus

Answer 2

neutron

Question 3

negative charge, no relevant mass, in electron cloud, decides how atoms bond with one another

Answer 3

electron

Question 4

Anything that has mass and takes up space.

Answer 4

matter

Question 5

A characteristic of a pure substance that can be observed without changing the substance’s composition.

Answer 5

physical properties

Question 6

A property of matter that describes a substance’s ability to participate in chemical reactions.

Answer 6

chemical properties

Question 7

A substance that cannot be broken down into simpler substances, and are the primary constituents of matter.

Answer 7

element

Question 8

Smallest unit (particle) of an element

Answer 8

atom

Question 9

An atom’s central core, containing protons and neutrons. Has virtually all of its mass.

Answer 9

atomic nucleus

Question 10

The region around the nucleus of an atom where electrons are likely to be found.

Answer 10

electron cloud

Question 11

the number of protons in the nucleus of an atom

Answer 11

atomic number

Question 12

A one or two letter abbreviation for an element.

Answer 12

atomic symbol

Question 13

the weighted average of the masses of the isotopes of an element

Answer 13

atomic mass

Question 14

atoms of the same element that have different numbers of neutrons

Answer 14

isotope

Question 15

a charged atom; gains its charge by having a different number of protons and electrons

Answer 15

ion

Question 16

the sum of the number of neutrons and protons in an atomic nucleus; the mass of a specific atom

Answer 16

mass number

Question 17

electrons on the outermost energy level of an atom

Answer 17

valence electrons

Question 18

Hydrogen has ___ valence electrons.

Answer 18

one

Question 19

Nitrogen has ___ valence electrons

Answer 19

five

Question 20

Chlorine has ___ valence electrons.

Answer 20

seven

Question 21

Calcium has ___ valence electrons.

Answer 21

two

Question 22

Xenon has ___ valence electrons.

Answer 22

eight

Question 23

Gallium has ___ valence electrons.

Answer 23

three

Question 24

two or more atoms joined together chemically

Answer 24

molecule

Question 25

molecule formed by the chemical combination of two or more elements

Answer 25

compound

Question 26

Symbols that show the elements in a compound and the ratio of atoms

Answer 26

chemical formula

Question 27

different orbits that electrons can take around the nucleus

Answer 27

electron shells (energy levels)

Question 28

electrons move in fixed in circular orbits around nucleus of an atoms

Answer 28

Bohr's model

Question 29

Diagram of an atom, ion or molecule in which each dot represents a valence electron

Answer 29

Lewis Dot Diagram

Question 30

refers to an outer main energy level occupied, in most cases, by eight electrons

Answer 30

noble gas configuration

Question 31

in forming compounds, atoms tend to achieve the electron configuration of a noble gas, 8 valence electrons

Answer 31

octet rule

Question 32

Formed when one or more electrons are transferred from one atom to another

Answer 32

ionic bond (definition)

Question 33

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

Answer 33

covalent bond (definition)

Question 34

metal + nonmetal

Answer 34

ionic bond (atom types)

Question 35

nonmetal + nonmetal

Answer 35

covalent bond (atom types)

Question 36

A starting material in a chemical reaction

Answer 36

reactants

Question 37

Ending materials in a chemical reaction.

Answer 37

products

Question 38

A combination of two or more substances that are not chemically combined

Answer 38

mixture

Question 39

A mixture that is not uniform in composition; components are not evenly distributed throughout the mixture

Answer 39

heterogeneous mixture

Question 40

A mixture in which substances are evenly distributed throughout the mixture

Answer 40

homogeneous mixture

Question 41

A homogeneous mixture of two or more substances

Answer 41

solution

Question 42

in atomic notation, the lower-left number

Answer 42

atomic number, number of protons

Question 43

in atomic notation, the upper-left number

Answer 43

mass number, protons + neutrons

Question 44

in atomic notation, the upper-right number

Answer 44

charge, protons - electrons

Question 45

MgO would have:

Answer 45

ionic bonds

Question 46

NO would have:

Answer 46

covalent bonds

Question 47

Atomic notation, # of protons

Answer 47

The atomic number, bottom left

Question 48

Atomic notation, # of neutrons

Answer 48

The mass number, top left, minus the number of protons

Question 49

Atomic notation, # of electrons

Answer 49

The number of protons minus the charge

Question 50

a material with only one element of atom present, such as pure copper (Cu)

Answer 50

pure substance, element

Question 51

a material with only one kind of compound present, like pure salt (NaCl)

Answer 51

pure substance, compound