unit 1 terms

Question 1

atomic mass

Answer 1

mass of an atom, measured in amu
-1/12 of a carbon-12 atom

Question 2

the mole

Answer 2

-atoms can’t be counted, reasonable amount of a substance
6.022 x 10^23 particles or formula units

Question 3

mass spectroscopy

Answer 3

-gives the mass-to-charge ratio
-separate isotopes according to mass
-used to find relative abundance/average atomic mass
-size of peaks is relative number of particles

Question 4

ion

Answer 4

has different number of electrons

Question 5

isotope

Answer 5

has different number of neutrons

Question 6

pure substances

Answer 6

-elements and compounds, 1 type of molecule

Question 7

mixtures

Answer 7

-homogeneous (solutions)
-heterogeneous

Question 8

law of definite proportions

Answer 8

ratio of the masses of the elements in any pure sample of that compound is always the same
-simple whole number ratios
-if ratio is different, not pure, mixture
-determine purity w empirical formula

Question 9

empirical formula

Answer 9

-assume have 100g sample, make percentage grams, grams to moles
-divide molar amounts by least amount of moles

Question 10

molecular formula

Answer 10

-calculate mass of empirical formula, divide compound mass by mass of empirical formula
-multiply subscripts by u

Question 11

coulombs law

Answer 11

-relationship between charged of particles and the distance between them
-bigger, more charge, stronger force

Question 12

photoelectron spectroscopy

Answer 12

-ionization energy
-amount of energy tells electrons location
-higher energy=electrons closer to nucleus
-more protons move to left, more charge, greater coulomb attraction

Question 13

Pauli exclusion principle (orbital notation)

Answer 13

-no two electrons can have the same set of 4 quantum numbers
-no atomic orbital can contain more than 2 electrons per orbital, and must have opposite spin on orbital

Question 14

Hunds Rule (orbital notation)

Answer 14

-most stable arrangement of electrons is that with maximum number of unpaired electrons because it minimizes electron-electron repulsions
-single electrons have parallel spins to reduce e/e repulsion

Question 14

alkali metals

Answer 14

1st, most reactive metal family, react violently w water

Question 14

alkaline earth metals

Answer 14

2nd, hydroxides of these provide basic solutions for water

Question 15

chalcogen family

Answer 15

6th, found in metal ores

Question 16

halogen family

Answer 16

7th, salt formers, modern lighting

Question 17

noble gas

Answer 17

8th, known for lack of reactivity

Question 18

atomic radius

Answer 18

increases down and to the left
-down: increasing energy level, outermost electron in last level
-across: adding more protons going right, gaining charge (coulomb attraction) since protons are charged in nucleus, radius shrinking since particles closer together

Question 19

ionization energy

Answer 19

-increases up and right
-energy it takes to remove an electron from an electron in the gas phase
-smaller radius, more coulomb attraction, greater ionization energy
-big change in ionization energy when removing core electrons (since closet to nucleus)
-exceptions b/t group 2 and 13 (decreases right) bc difference in s and p orbitals
-group 15 and 16 bc more electron-electron repulsion easier to remove

Question 20

ionic radii-cations

Answer 20

(pos charge) lost electron
-smaller than their atom
-remain electrons more attraction from nucleus, shrinking radius (ratio changes),
-less electron-electron repulsion

Question 21

ionic radii-anions

Answer 21

(neg charge) gain electron
-larger than their atom
-more electrons means more electron-electron repulsion, increasing the radius

Question 22

Isoelectric

Answer 22

-things w same number of electrons
-focus on protons to answer question (if more protons, greater charge, smaller radius)

Question 23

Electronegativity

Answer 23

-ability of an atom in a molecule to attract electrons to itself
-increases up and right
-atoms are smaller, more easily feel the charge of the nucleus
-less shielding in elements with less energy shells
-less shielding, nucleus more easily feel the charge

Question 24

electron affinity

Answer 24

-energy change that occurs when an electron is added to a gaseous atom
-opp. of ionization energy
-usually negative since energy given off when electron added
-in general increases to the right

Question 25

reactivity

Answer 25

-elements in same group react the same way with other compounds
-due to # of valence electrons
-same ending to their electron configurations
-same oxidation numbers (ion form)

Question 26

valence electrons

Answer 26

electrons in outermost energy levels

Question 27

cores electrons

Answer 27

electrons not in the outermost energy level

Question 28

oxidation number

Answer 28

most common ion that forms for a given elements
-based on valence electrons