2.1 Periodic Trends

Question 1

Atomic radius (size of neutral atom) trend

Answer 1

l
                        l
                        l
                        v
Fr

Question 2

Ionic radius (size of a charged atom) trend

Answer 2

Cations (metals):
-The larger the charge, the smaller the atom.
o O
Mg Mg2+

Anion (non-metals)
-The smaller the charge, the larger the atom.
o O
S S2-

Question 3

What is an iso-electronic series and how do you compare their size?

Answer 3

• An iso-electronic series is a series of ions with the same number of electrons.
• The ion with the most positive charge is the smallest atom
• The ion with the most negative charge is the largest atom.

Question 4

What is 1st Ionization Energy, and what is the trend?

Answer 4

The energy used to lose an e-.
                    He
                      ^
                       l
                       l
                       l
------------------->

Question 5

What are the exceptions to 1st Ionization Energy?

Answer 5

Group 5A elements (N, P, As) have higher 1st Ionization Energies than group 6A elements (O, S, Se)

Question 6

What is electron affinity, and what is the trend?

Answer 6

The energy used to gain an e-.

more F
————————–> Cl
negative Br
I

Question 7

What are the exceptions to electron affinity?

Answer 7

Be an N are close to zero.

Question 8

What is electronegativity, and what is the trend?

Answer 8

-How closely an atoms nucleus holds electrons to it.
-N, O, & F are the most electronegative.
F
^
l
l
l
————->