10/4 notes

Question 1

are cations smaller or larger than their neutral atoms

Answer 1

smaller

fewer electrons and they are pulled closer to nucleus

Question 2

are anions smaller or larger than their neutral atoms

Answer 2

larger

more electrons (further from nucleus due to electron-electron repulsion)

Question 3

what is first ionization energy

Answer 3

the energy required to pull the first electron (easiest to pull off)from an atom

Question 4

what are the two kinks with first ionization energy

Answer 4

Be -> B
and
N-> O

Question 5

what is second ionization energy

Answer 5

energies are always larger than the first IE

Question 6

3rd ionization energy

Answer 6

always larger than the second, etc

Question 7

electron affinity (EA)

Answer 7

Energy change when an electron is added to an atom. This produces an anion.

Question 8

what are the halogens

Answer 8

F, Cl, Br, I

Question 9

what is a halogen

Answer 9

they have the most negative EA. They are negative because energy is released when the added electron binds to an atom

Question 10

is the first EA more positive or more negative across a row

Answer 10

more negative (excluding the noble gases)

Question 11

is there a clear trend down a colum

Answer 11

no

Question 12

what is noble gases EA

Answer 12

clsoer to zero (sometimes even negative)

Question 13

what are noble gases IE’s

Answer 13

very high, so hard to pull off electron

Question 14

when EA’s are close to zero

Answer 14

there is no advantage in adding an electron

Question 15

why is there a kink between Be and B

Answer 15

B has a valence electron in 2p orbital while Be has one in 2s orbital so it has a lower IE energy

Question 16

why is there a kink between N and O

Answer 16

Oxygen has additional electron in 2p orbital which causes e-e repulsion and makes it easier to remove an electron than in N atom

Question 17

Electron-electron repulsions

Answer 17

due to their like charges, electron pairs orient themselves as far away as possible from each other, causing the electron cloud to expand

Question 18

why are IE always positive

Answer 18

because energy must be supplied (an endothermic energy change) to separate electrons from atoms.

Question 19

Why are successive I.E.s always larger?

Answer 19

because for the same nuclear charge (positive pull of the nucleus) there are fewer electrons each time one is removed, thus more energy is required to remove successive electrons.

Question 20

why does a large jump in ionization energy occur

Answer 20

When electrons are removed in succession from an element, the transition from removing valence electrons to removing core electrons

Question 21

What trends are observed for the first E.A.?

Answer 21

Tend to be negative, meaning energy is released when the electron is added

Question 22

Why are noble gases unreactive?

Answer 22

they have fully filled outer orbital configuration due to which they are very stable and have minimum energy.