Science Review

Refer to your Periodic Table

What is the charge of a Sodium (Na) ion?

• +11

• +1

• -1

• -11

Answer explanation

Na is in Group 1; it has 1 valence electron. It will lose that valence electron

If an atom has 3 valence electrons, what will be its charge when it forms an ion?

• +3

• +5

• -3

• -5

Answer explanation

The atom will lose its outer 3 electrons when it becomes an ion to expose a full valence shell.

If an atom gains 3 electrons, what will be it's ion charge?

• +3

• -3

• +5

• -5

If an atom has 1 valence electron, what charge will it have when it becomes an ion?

• +1

• -1

• +7

• -7

Answer explanation

It will lose its one valence electron.

Refer to your Periodic Table.

How many valence electrons does a Bromine atom have?

• 35

• 17

• 7

• 80

Answer explanation

Bromine is in Group 17. All elements in Group 17 (also known as 7A) have 7 valence electrons.

If an atom has 6 valence electrons, what charge will it have when it becomes an ion?

• +2

• -2

• +6

• -6

Answer explanation

If it has 6 valence electrons, it needs to gain 2 more to complete its valence shell.

Refer to your Periodic Table.

If an atom is an alkaline earth metal, what charge will it have when it forms an ion?

• +2

• -2

• -6

• +6

• it will not form an ion; it is inert

Refer to your Periodic Table.

What is a general chemical characteristic of metals? (Notice their location on the Periodic Table)

• They tend to gain electrons

• They tend to lose electrons

• They have complete valence shells therefore do not gain or lose electrons

Answer explanation

In general, atoms with fewer than 4 valence electrons have metallic properties

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Refer to your Periodic Table.

What is true about noble gases?

(Choose TWO correct answers)

• They have a filled valence shell

• They are inert

• They are very reactive

• They have 18 valence electrons

O^2-

Choose TWO correct statements regarding this ion

• Gained electrons to become charged

• Cation

• Anion

• Lost electrons to become charged

Answer explanation

Electrons are negative! In order for the ion to become negative, the atom must GAIN electrons