What is everything around us made of?

What is the smallest unit of matter?

Which of these is a molecule?

Which of the following is made up of only one type of atom?

What do atoms combine to form?

What is the center of an atom called?

Which particle has a negative charge?

Which of these is NOT a state of matter?

Which of the following is a compound?

How many atoms are in a water molecule (H₂O)?