Chem Mid Term

Front 1

atomic number

Back 1

the number of protons in the nucleus of an atom.

Front 2

atomic radius

Back 2

the distance from the nucleus to the outermost electrons of an atom.

Front 3

aufbau principle

Back 3

a rule that electrons will occupy the lowest energy subshell that is available.o The energy state of a subshell increases as the distance from the nucleus increases.

Front 4

chemical family

Back 4

a vertical column in the periodic table of elements.o Elements in the same family have the same number of valence electrons and have similar chemical properties.

Front 5

hund's rule

Back 5

a rule stating that, within a subshell, electrons will occupy all of the unoccupied orbitals before sharing orbitals.o A subshell will never contain an orbital with two electrons and another orbital with zero electrons.

Front 6

a region in space occupied by an electron or pair of electrons.o Formally, an orbital is a mathematical function that describes the probability of an electron (or pair of electrons) being found in a particular space.

Back 6

orbital

Front 7

pauli exclusion

Back 7

a rule that states that no two electrons can have exactly the same location and state. o If two electrons share the same shell, subshell, and orbital, they must have different spins.

 

Front 8

shell

Back 8

a particular region where electrons can orbit the nucleus of an atom.

Front 9

spin

Back 9

a property of electrons that causes them to have an angular momentum and magnetism.o Electron spin is shown with arrows:

Front 10

clockwise

Back 10

An uparrow represents____spin.

Front 11

counterclockwise

Back 11

A down arrow represents ______ spin.

Front 12

subshell

Back 12

a subdivision of a shell, designated as s, p, d, and f

Front 13

precipitate

Back 13

a solid that forms and settles out of a liquid mixture

Front 14

product

Back 14

a substance produced in a chemcial reaction

Front 15

reactant

Back 15

a substance present at the start of a reaction

Front 16

solid

Back 16

a form of matter that has a definite shape and volume

Front 17

solution

Back 17

a homogeneous mixture; consits of solutes dissolved in a solvent

Front 18

vapor

Back 18

describes the gaseous state of a substance that is generally a liquid or solid at room temperature

Front 19

absolute zero

Back 19

the zero point on the Kelvin temperature scale, equivalent to -273.15C (3.2)

Front 20

atomic mass

Back 20

the mass of an atom expressed in atomic mass units

Front 21

atom

Back 21

the basic unit of an element

Front 22

atomic mass unit

Back 22

a unit of mass used to express atomic and molecular weights, equal to one-twelfth of the mass of an atom of carbon-12.

Front 23

atomic number

Back 23

The number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table

Front 24

electron

Back 24

A stable subatomic particle with a charge of negative electricity

Front 25

isotopes

Back 25

Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei

Front 26

mass number

Back 26

The total number of protons and neutrons in a nucleus.

Front 27

neutron

Back 27

a subatomic particle contained in the atomic nucleus. It has no net electric charge, unlike the proton's positive electric charge. The number of neutrons in an atomic nucleus determines the isotope of that element.

Front 28

nucleus

Back 28

The central and most important part of an object, movement, or group, forming the basis for its activity and growth.

Front 29

proton

Back 29

A stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron.