Which element makes up over twenty percent of the Earth's atmosphere?

Potassium

Helium

Oxygen

Calcium

What system uses calcium to help transmit impulses through your body?

Nervous system


Circulatory system


Muscular System


Respiratory system


The sun is a big ball of...

Hot liquid


Gases


Light


Metal


What is the symbol for potassium?

P


Po


Ta


K