What is every substance in the universe made up of?

How many types of atoms are there?

What does STM stand for?

What microscopes are used to see atoms?

What are elements?

What is the air you breathe made up of?

What are the two classifications of elements?

What are some examples of metallic elements?

What are some properties of metallic elements?

What are some examples of non-metallic elements?

Which element is a liquid at room temperature?

What happens to non-metallic elements at room temperature?

What are some of the properties of non-metallic elements?

How many known elements are there?

How many of the elements occur naturally?

What helps scientists understand the physical properties of elements?

What can atoms in elements exist as?

What are physical properties?

What are monatomic elements?

How many monatomic elements are there?

What are the 6 monatomic elements?

What are molecules?

How many oxygen atoms does each oxygen molecule contain?

What are lattices?

What can metals and non-metals both form?