Periodicity

Question 1

Ionization energy

Answer 1

the minimum required energy to eject an electron out of a neutral atom or molecule in its ground state

Question 2

Ionization energy trend as you move down a group

Answer 2

decreases due to increased nuclear shielding

Question 3

Ionization energy trend as you move across a period

Answer 3

increases due to increased nuclear charge

Question 4

Ionization energy trend exceptions

Answer 4

Be to B, ionization of an electron from the first p orbital makes an ion more stable so requires less energy

N to O, ionization of an electron from the only paired orbital makes the atom more stable so requires less energy

Question 5

Periodicity

Answer 5

trends in the periodic table

Question 6

Atomic radius

Answer 6

The radius of a given atom

Question 7

Atomic radius trend across a period

Answer 7

atomic radius decreases, this is because each element has an additional proton, creating a greater nuclear charge (more attraction to electrons).

Question 8

Atomic radius trend down a group

Answer 8

the atomic radius increases as you add an additional energy level.

Question 9

effective nuclear charge, Zeff

Answer 9

As you add energy levels to an element, the valence electrons become shielded by the inner core electrons.

Question 10

Ionic radius

Answer 10

The radius of an atom that has gained or lost electrons

Question 11

Cation

Answer 11

• positively charged
• lost electrons
• radius smaller than parent atom
• Groups 1, 2 and 13
• charge is equal to the number of valence electrons.
• The more electrons lost the smaller the radius.

Question 12

Anion

Answer 12

• negatively charged
• gain electrons
• radius larger than parent atom
• Groups 15, 16 and 17
• charge is equal to the number of electrons needed to get to 18.
• The more electrons gained the larger the radius.

Question 13

Electron affinity (EA)

Answer 13

the energy released when an additional electron is attached to a neutral atom or molecule.

Question 14

Electron affinity trend across a period

Answer 14

As you move across a period, electron affinity increases. The higher the nuclear charge, so the more energy is released when an electron is added. (no trend going down)

Question 15

Electronegativity (x)

Answer 15

a measure of the ability of an atom to attract electrons in a chemical bond to itself.

Question 16

Electronegativity trend across a period

Answer 16

increases across a period. Smaller atoms with nearly complete electron shells will attract electrons more easily.

Question 17

Electronegativity trend down a group

Answer 17

decreases down a group. Smaller atoms with nearly complete electron shells will attract electrons more easily.

Question 18

Spectral line convergence

Answer 18

The wavelength that represents ionization of an electron

Question 19

Successive ionization energy

Answer 19

The energy required to remove a second or more electron from an atom

Question 20

Successive ionization energy trend

Answer 20

Increases, because the number of protons now exceeds the number of remaining electrons (increased attraction!) and electron-electron repulsion decreases.

This increases until the next stable noble gas configuration is reached at which point the energy increases sharply!