Electron Configuration And Nuclear Chemistry

Front 1

Electron configuration of cations

Back 1

Electrons are removed from outer shell (shell with highest number) first

Front 2

Excited state

Back 2

Look for electron configuration that appears to have skipped a shell.

Front 3

Positron

Back 3

Positively-charged electron

Front 4

Stable nuclei (not radioactive)

Back 4

Even numbers of protons and/or neutrons

Neutron to proton ratio (N/Z) equal to 1 for elements equal to or lower than 20 (Ca) --> belt of stability

Magic numbers are more stable

*Heavy elements are almost all radioactive

Front 5

Gamma ray

Back 5

High-energy photon with no mass and the most penetrating power

Front 6

Alpha particle

Back 6

Equal to mass of helium nucleus (2 protons and 2 neutrons) and has least penetrating power

Front 7

Strong nuclear force a/k/a nuclear binding energy

Back 7

Holds protons together in nucleus in opposition to repulsion between protons but only works across very short distances

Front 8

Nuclear chemistry

Back 8

Different from other areas of chemistry because it deals with the nucleus and protons rather than electrons

Front 9

Relationship between mass (matter) and energy

Back 9

E=mc^2

Mass/matter and energy are the same thing in different forms

Front 10

Stability of products v. reactants in nuclear chemistry

Back 10

Products are more stable (and slightly lighter) than reactants because they release energy through radioactive decay

Front 11

Energy difference between orbitals

Back 11

Energy difference is greater between lower orbitals than between higher orbitals

Front 12

Max. number of orbitals in each electron shell

Back 12

n^2

s shell has 1 orbital

p shell has 3 orbitals

d shell has 5 orbitals

f shell has 7 orbitals

Front 13

Max. number of electrons

Back 13

2n^2

Front 14

Pauli exclusion principle

Back 14

No electron can have the same 4 quantum numbers

Front 15

n (principal number)

Back 15

Gives the shell number (i.e. 1s, 2s, 3d)

Cannot be less than 1

Front 16

l (azimuthal number)

Back 16

Gives subshell number (i.e. s, p, d, or f)

Cannot be higher than n-1

s=0

p=1

d=2

f=3

Front 17

ml (magnetic number)

Back 17

Gives specific orbital

Must be between -l and +l

Front 18

ms (spin number)

Back 18

Tells whether spin is up or down

Can only be -1/2 or +1/2

Front 19

Paramagnetic

Back 19

Electrons are not all paired

*if element has an odd number of electrons, then it is definitely paramagnetic but elements with even number of electrons can also be paramagnetic

Front 20

Diamagnetic

Back 20

All electrons are paired, i.e. valence shell is full

Front 21

Chemical identity

Back 21

Determined by number of protons and electrons, NOT by number of neutrons

Front 22

Alpha decay (or alpha emission)

Back 22

Reduces mass number

Front 23

Beta decay (or beta emission)

Back 23

Lowers N/Z ratio

-converts neutrons into protons

(fewer neutrons, lower N/Z ratio)

Front 24

Positron emission or electron capture

Back 24

Increases N/Z ratio

-converts protons to neutrons

(more neutrons, higher N/Z ratio)

Front 25

Gamma decay

Back 25

Nucleus relaxes to ground state

Front 26

Mass defect

Back 26

Amount of mass converted to (binding) energy

-explains why nucleus is lighter than the combined weight of its nucleons

Front 27

Fusion

Back 27

Lighter elements combine to form a heavier one

Front 28

Fission

Back 28

Heavier elements separate into lighter ones

Front 29

Nuclear binding energy

Back 29

Measures stability of element (higher nuclear binding energy per nucleon means greater stability)

-The closer an element is to Fe56 (the most stable nucleus on Earth), the more stable it is likely to be