Unit 2 Vocabulary

Question 1

Dalton’s Atomic Theory

Answer 1

Elements = indivisible paricles called atoms;
Atoms of an element are identical (same mass) and atoms of different elements have different masses;
Compounds form when atoms of different element combine;
Atoms of element don’t change into different types of atoms in a chemical reaction

Question 2

Mass number

Answer 2

The sum of the number of neutrons and protons in the nucleus

Question 3

Changes to Daltons Atomic Theory

Answer 3

Isotopes- atoms of same element with different mass

Subatomic particles- atoms are divisible

Question 4

Photon

Answer 4

Quantum of energy; each has specific wavelength frequency; given off as electrons bounce down energy levels; amount of energy depends on space between energy levels

Question 5

Quantum

Answer 5

(Planck) Smallest amount of energy that can be gained or lost

Question 6

Bright- Line Spectrum

Answer 6

Set of lines produced by an exited element (as electrons jump down energy levels, they most lose energy- in form of photon); each element has its own due to spacing between energy levels

Question 7

Excited State

Answer 7

Some electrons are in higher than ground-state levels-

electrons jump up and gain energy/ fall down and give off energy (photon)

Question 8

Ground State

Answer 8

All electrons are in their lowest possible energy levels

Question 9

Bohr’s theory

Answer 9

Electrons must lose energy- atoms don’t obey laws of physics; as long as electrons are on their energy levels, they don’t lose energy; each energy level holds a certain number of electrons

Question 10

Planck’s constant

Answer 10

Relates energy of a photon to its frequency

Question 11

Thomson’s Atomic Model

Answer 11

(Plum Pudding Model) An atom is a ball of positive charge with electrons scattered through it

Question 12

Thomson

Answer 12

Discovers electrons through Crook’s Tube experiment;

Also discovers neutrons

Question 13

Rutherford’s Atomic Model

Answer 13

(Gold foil experiment) An atom is mostly empty space- it has a small, dense, positive nuclues surronded by orbiting electrons

Question 14

Bohrs Atomic Model

Answer 14

An atom is mostly empty space- it has a small, dense, positive nuclues surronded by orbiting electrons on Definate Energy Levels!

Question 15

Exothermic Reaction

Answer 15

Releases heat energy; energy leaves system; feels hot

Question 16

Endothermic Reaction

Answer 16

Absorbs heat energy to power the change fo the reaction; feels cold

Question 17

Activation Energy

Answer 17

Energy required to start a chemical reaction

Question 18

Heisenberg Uncertainty Principle

Answer 18

It is impossible to know the location and velocity of an electron at the same time- you can only predict areas of finding and e-

Question 19

PEL (n)

Answer 19

(Principal energy levels) n=1-7; made of 1 or more sublevels

Question 20

Sublevels

Answer 20

of sublevels = PEL #
ex. PEL 3 has 3 sublevels;
Each sublevel is associated with a certain amount of energy; each sublevel is made up of 1 or more orbitals
s(2e) (1 orbital); p(6e) (3o); d(10e) (5o); f(14e) (7o)

Question 21

Orbitals

Answer 21

Region of space occupied by no more than 2 electrons with opposite spins

Question 22

Electron energy level breakdown

Answer 22

PEL(n) n =1-7
Sublevels=PEL number (ex. PEL 3 has 3 sublevels)
Orbitals=n squared
Electrons= 2n squared

Question 23

How are two electron in different energy levels (or sublevels) different?

Answer 23

They have different amounts of energy

Question 24

Only electrons in outermost PEL-determine activity of an element. Can be found by counting by roman numeral at top of periodic table.

Answer 24

Valence Electrons

Question 25

Metric Breakdown

Answer 25

Kilo: 10 3
Centi: 10 -2
Milli: 10 -3
Micro: 10 -6
Nano: 10 -9

Question 26

Ion

Answer 26

an atom or a group of atoms that has a positive or negative charge, must have outer energy level(shell) filled

Question 27

a positively charged ion

Answer 27

cation

Question 28

a negatively charged ion

Answer 28

anion

Question 29

elements in groups 3-12, able to make various charges

Answer 29

Transitional Metals

Question 30

elements in group 1(not hydrogen)

Answer 30

alkali metals

Question 31

elements in group 2

Answer 31

alkaline earth metals

Question 32

elements in group 17

Answer 32

halogens

Question 33

elements in group 18

Answer 33

noble gases

Question 34

2 of the same atoms in a molecule, 7 elements naturally occur: Br₂, I₂, N₂, Cl₂, H₂, O₂, F₂, acronym BrINClHOF

Answer 34

diatomic molecules

Question 35

group

Answer 35

vertical column of elements, 18 groups

Question 36

period

Answer 36

horizontal row of elements, 7 periods

Question 37

have 1 electron in outer shell, have 1+ charge when forming ions

Answer 37

group 1 metals

Question 38

have 2 electrons in outer shell, have 2+ charge when forming ions

Answer 38

group 2 metals

Question 39

have 3 electrons in outer shell, have a 3+ charge when forming ions

Answer 39

group 13 metals

Question 40

have 5 electrons in outer shell, have a 3- charge when forming ions

Answer 40

group 15 nonmetals

Question 41

have 6 electrons in outer shell, have a 2- charge when forming ions

Answer 41

group 16 nonmetals

Question 42

have 7 electrons in outer shell, have a 1- charge when forming ions

Answer 42

group 17 nonmetals

Question 43

ionic compounds

Answer 43

must contain at least one cation and one anion, overall charge must equal zero, for writing identify cation and anion and charges they will form, determine number of cations and anions necessary for overall charge to equal zero(lowest common multiple), write symbol of cation↓ⁿ and symbol anion ↓ⁿ

Question 44

naming cations

Answer 44

element name + ion,

ex. Na+ = sodium ion, magnesium ion = Mg²=

Question 45

naming anions

Answer 45

changing ending of element name to -ide, then add ion,

ex. F- = fluoride ion, O²- = oxide ion, S²- = sulfide ion, P³- = phosphide ion, iodide ion = I-

Question 46

equation for number of electrons held in each energy level

Answer 46

2(energy level #²)

Question 47

have properties of both metals and nonmetals, found on the staircase

Answer 47

metalloids