Unit 4.2 Electron Configurations and Periodic Trends

Question 1

Atomic Radius

Answer 1

Half the distance between 2 nuclei of identical atoms bonded together.

Trend- Periods: decrease left to right
Groups: increase top to bottom

Only trend that is different

Question 2

Ionization Energy

Answer 2

The energy it takes to remove electrons from an atom

Trend- Periods: increase left to right
Groups- decrease top to bottom

Question 3

Electron Affinity

Answer 3

The energy chang that occurs when an electron is added to an atom

Trend- Periods: increase left to right
Groups decrease top to bottom

Question 4

Electronegativity

Answer 4

The measure of the ability of an atom in a compound to attract a valence electron from another compound

Trend- Periods: increase left to right
Groups- decrease top to bottom

Question 5

How many valence electrons does group ONE have?

Answer 5

G1= 1 ve

Question 6

How many valence electrons does group TWO have?

Answer 6

G2= 2 ve

Question 7

What formula do you use to find the number of valence electrons in groups 13 through 18?

Answer 7

ve= group # - 10

Question 8

How many valence electrons does group 14 have?

Answer 8

14-10= 4 ve

Question 9

Practice Question
arrange these elements in decreasing electron affinity: C, O, Li, Na, Rb, F

Answer 9

F, O, C, Li, Na, Rb

Question 10

Practice Question
arrange these elements in increasing atomic radius: C, O, Li, Na, Rb, F

Answer 10

F, O, C, Li, Na, Rb

Question 11

Practice Question
arrange the following in decreasing ionization energy: Li, O, C, K, Ne, F

Answer 11

Ne, F, O, C, Li, K

Question 12

Practice Question
arrange the following in increasing electronegativity: C, N, O, Br, S

Answer 12

C, Br, N, S, O or C, Br, S, N, C

Question 13

Practice Question
arrange the following in increasing electron affinity: E=2s^2 2p5
G=4d^10 5s^2 5p^5 L=5d^10 6s^2 6p^5

Answer 13

L, G, E

Remember to look at the largest PQN when determining the period

Remember to use the group formulas when determining the group