gen chem what if we locked in

Atomic number

The number of protons in a given element

Mass number

The sum of an element’s protons and neutrons

Atomic mass

Is generally equal to the mass number

Isotopes

Atoms of a given element with the same atomic number that have different mass number

How isotopes differ

# of neutrons

Element followed by mass number

How isotopes are identified

Hydrogen isotopes

Protium

Deuterium

Tritium

Protium mass number

1

Deuterium mass number

2

Tritium mass number

3

Atomic weight

The weighted average of the naturally occurring isotopes of an element

Atomic weights

The periodic table lists

Rutherford model

An atom has a dense nucleus that is only a small fraction of the atom volume

Bohr model

A dense, positively charged nucleus is surrounded by electrons revolving around a nucleus

Quantum

The smallest possible indivisible unit of property

Quantization

There isn’t an infinite range of energy levels available to an electron, and electrons can exist only at certain levels

Farther from an atom nucleus

The energy of an electron increases

Atomic absorption spectrum

For an electron to jump from a lower energy level to a higher one it must absorb a specific amount of energy precisely equal to the energy difference between the two levels

Unique to each element

The atomic absorption spectrum

Atomic emission spectrum

The EM energy emitted corresponds to a frequency in the visible light range

Atomic emission spectrum cause

When electrons return from the excited state to the ground state, they emit a specific amount of energy that is exactly equal to the energy difference between the two levels

Quantum mechanical model

Electrons don’t travel in defined orbits but rather are localized in orbital

Orbital

A region of space around the nucleus defined by the probability of finding an electron in that region of space

Heisenberg uncertainty principle

IT’s impossible to know both an electron’s position and its momentum exactly the same time

Can only know one or the other

Quantum number

n

l

m_l

m_s

Principal quantum number

n

Describes the average energy of a shell

Azimuthal quantum number

l

Describes the subshells within a given principal energy level

Subshells

s

p

d

f

Magnetic quantum number

m_l

Specifies the particular orbital within a subshell where an electron is likely to be found at a given time

Spin quantum number

m_s

indicates the spin rotation of an electron in an orbital

Possible spin orientations

+1/2

-1/2

Electron figuration

Uses spectroscopic notation to designate the location of electrons

Spectroscopic notation

Combining the n and l values as a number and letter, respectively

n+1 rule

Electrons fill the principal energy levels and subshells according to increasing energy

Hund’s rule

The subshells with multiple orbitals (ie. p, d, and f) fill electrons so that every orbital inn a subshell gets one electron before any of them get a seconds

Paramagnetic materials

have unpaired electrons that align with magnetic fields, attracting that material to a magnet

Diamagnetic materials

Have all paired electrons, which can’t be easily be realigned, and they are repelled by magnets

Valence electrons

The electrons in the outermost shell available for interaction/bonding with other atoms

Representative elements valence electron orbitals

s and/or p

Transition elements valence electron orbitals

s and either d or f

Representative metals

Groups 1, 2, and 13-18

Planck relation

Light energy is directly linked to its frequency

Planck relation formula

E=hv

E= energy of a single photon in J

h= Planck’s constant

v= frequency of a light wave in Hz

Planck’s constant

6.626×10^-34

Periods

Rows of the periodic table and are based on the same principal energy level/n

Groups

Columns of the periodic table

Same group characteristics

Same valence shell electron configuration

Metals characteristics

lustrous, conduct electricity well, malleable, and ductile

Lustrous

Shiny

Malleability

Allows a material to be physically manipulated without cracking or breaking

Ductile

A material can be stretched into a thin wire without breaking

Left side and middle of the periodic table

Where metals are found

Nonmetals characteristics

dull, poor conductors of electricity, brittle

Right side of the periodic table

Where nonmetals are

Metalloid characteristics

Have characteristics of both metals and nonmetals

Stair step pattern starting with Boron/B

Where metalloids are found

Z_eff

Effective nuclear charge

Effective nuclear charge

The net positive charge experienced by electrons in the valence shell and forms the foundation for all periodic trends

Effective nuclear charge periodic table trend

Increase from left to right across a period with a small increase from bottom to top in a group

Effective nuclear charge cause

Valence electrons become increasingly separated from the nucleus as the principal energy level/n increases from top to bottom in a group

Atomic radius periodic table trend

Increases from right to left across a period and increases down a group

THE ONLY PROPERTY THAT EXHIBITS THIS

Ionic radius

The size of a charged species

The metalloid boundary

Where the largest nonmetallic ionic radii and smallest metallic ionic radii exist

Smaller than their corresponding neutral atom

Cations are

Larger than their corresponding neutral atom

Anions are

Ionization energy

The amount of energy necessary to remove an electron from the valence shell of a gaseous species

Ionization energy periodic table trend

Increases from left to right across a period and increases up a group

Electron affinity

The amount of energy released when a gaseous species gains an electron in its valence shell

Electron affinity period table trend

Increases from left to right across a period and increases up a group

Electronegativity

A measure of the attractive force of the nucleus for electrons within a bond

Electronegativity period table trend

Increases from left to right across a period and increases up a group

Electronegativity period table trend exceptions

The first three noble gases

Electronegativity period table trend exception cause

Those elements are unlikely to form bonds, particular due to having a full octet

Second ionization energy

First ionization energy is smaller than the

Active metals

Not found in their neutral forms, and are always found in ionic compounds, minerals, or ores

Their respective electron losses result in a full octet

Reason why Groups IA and IIA have low ionization energy is

Alkali metals oxidation state

+1

Alkali metals and electron loss

Prefer to lose 1 electron to achieve a noble gas-like configuration/a a full octet

The most reactive metals

Alkali and alkaline earth metals

Alkaline earth metals oxidation state

+2

Alkaline earth metals and electron loss

Can lose two electrons to achieve noble gas-like configurations/a full octet

Chalcogen nonmetal oxidation state

-2

Chalcogen metal oxidation state

+6

Chalcogen nonmetals and electrons gain

Gain 2 electrons to achieve noble gas configuration/a full octet

Chalcogen metals and electron loss

Lose 6 electrons to achieve noble gas configuration/a full octet

Halogen oxidation state

-1

Halogen and electron gain

Gain 1 electron to obtain a preferred noble gas configuration/a full octet

Noble gases and electrons

Prefer not to take up or lose electrons due to their full valence electron shell

Transition metal oxidation state

There are multiple

Elements will form bonds to attain

A noble gas like configuration

Octet rule

Elements will be most stable with 8 valence electrons

Incomplete octet octet rule exception

Stable with fewer than 8 electrons

Incomplete octet octet rule exception examples

H, He, Li, Be, B

Expanded octet octet rule exception

Stable with more than 8 electrons

Expanded octet octet rule exception examples

All elements in period 3 or greater

Odd number electrons octet rule exceptions

Compounds with an odd number of electrons can’t have 8 electrons on each element

Ionic bond

Formed via the transfer of one or more electrons from an element with a relatively low ionization energy to an element with a relatively high ionization energy

ΔEN for ionic bonds

Between elements with large differences resulting in >1.7

Cation

Positively chargedion

Anion

Negative ion