Which of these element are found before Iron in the periodic table?

• Cobalt

• Copper

• Potassium

• Nickel

• Manganese

The mass of Iodine is ______________.

• 53

• 126.9

• 17

• 5

Lithium is in the 1st column of the 2nd row. What is the atomic number for it?

• 6.941

• 2

• 3

• 1

If potassium has an atomic number of 19, then how many protons and electrons does it have?

• 19

• 38

• 1

• 18

The chemical symbol for Zinc is

• zn

• ZN

• Zn

• zN

What family (or column) of the periodic table is He?

• alkaloid

• metal

• noble gas

• halogen

How many valence electrons does Si have?

• 2

• 10

• 1

• 4

How many valence electrons does phosphorus have?

• 2

• 5

• 4

• 3

How many valence electrons does Aluminum have?

• 3

• 2

• 1

• 4

How many valence electrons does magnesium have?

• 1

• 2

• 3

• 4