Valence Electrons and Ions

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Multiple Choice

How many valence electrons do the elements in group 15 (group 5A) have?

• 1

• 5

• 15

• 8

Match

Match the following elements to the correct number of valence electrons

• oxygen

• helium

• neon

• silicon

• chlorine

6

2

8

4

7

• 6

• 2

• 8

• 4

• 7

Reorder

Reorder the following from LEAST to MOST valence electrons

• hydrogen

• magnesium

• aluminum

• carbon

• sulfur

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Reorder

Reorder the following elements from LOWEST to HIGHEST period

• helium

• beryllium

• phosphorous

• calcium

• iodine

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Match

Match the following elements to the correct number of electron shells:

• iodine

• potassium

• sulfur

• oxygen

• hydrogen

5

4

3

2

1

• 5

• 4

• 3

• 2

• 1

Open Ended

In your own words, explain why it is important to know the number of valence electrons in an atom.

Multiple Select

Which elements are noble gases? Select all that apply.

• helium

• nitrogen

• hydrogen

• neon

• argon

Fill in the Blanks

Which element is the only one that does NOT obey the octet rule?

Multiple Select

What can happen for an atom to form a chemical bond? Select all that apply.

• an atom can gain electrons from another atom

• an atom can lose electrons from another atom

• an atom can share electrons with another atom

• an atom can undergo a nuclear reaction to become a different element

Open Ended

In your own words, explain why atoms form bonds to follow the octet rule

​This table compares the group number to the ion that an element will form. Note that elements in the same group all form ions with the same charge--this is because the number of valence electrons is related to the number of electrons it will gain or lose when forming an ion.

Multiple Choice

Select the best response to fill in the blanks:

An atom with two valence electrons will _____ two valence electrons to become a _____ .

• lose... cation

• gain...cation

• lose...anion

• gain....anion

Multiple Choice

Select the best response to fill in the blanks:

An atoms with six valence electrons will _____ two valence electrons to become a _____ .

• lose... cation

• gain...cation

• lose...anion

• gain....anion

Multiple Choice

Examine the shell model of nitrogen. What type of ion will nitrogen form? 

• a cation, N³⁺

• an anion, N³⁺

• a cation, N^3-

• an anion, N^3-

Open Ended

Examine the shell models for calcium and oxygen. Which of these atoms will form an anion? Give the charge (number and sign) for the anion that will form.