Grantham Science: Valence Electrons and Reactivity

The students will…

Know that the atomic number is the element’s
identity (# of Protons)

Understand that valence electrons (electrons in
the outermost shell) determines an atom’s
reactivity

Be able to look at Bohr models and determine if
an atom is reactive or not and who they will
react with

Identity Review

The atomic #

●The identity of the element

●The # of protons in the atom

●The periodic table is arranged
in order based on the atomic
number

Multiple Choice

How many protons does Argon have?

• 18

• 22

• 40

Multiple Choice

How many valence electrons does this atom have?

• 2

• 8

• 3

Multiple Choice

How many valence electrons does this atom have?

• 1

• 2

• 8

Multiple Choice

How many valence electrons does this atom have?

• 7

• 2

• 5

• 8

What do you notice different
between the atoms on the left vs the
right?

1. Which shell is the outer

shell?

2. How many valence

electrons does each atom
have?

3. Is the outermost shell full?

4. Is it reactive or

nonreactive?

Multiple Choice

Is this atom reactive?

• Yes

• No

Multiple Choice

Is this atom reactive?

• Yes

• No

Multiple Choice

Is this atom reactive?

• Yes

• No

Multiple Choice

Is this atom reactive?

• Yes

• No

Multiple Choice

Is this atom reactive?

• Yes

• No

​Elements in the same family/group are similar to each other. They are chemically similar!

Same # of valence electrons!

Multiple Choice

How many valence electrons will elements in group 1 have?

• 1

• 7

• 2

• 8

Multiple Choice

How many valence electrons will elements in group 13 have?

• 1

• 3

• 13

• 8

Multiple Choice

How many valence electrons will elements in group 17 have?

• 1

• 7

• 17

• 8

• 18