What are the three smaller particles that make up an atom?

(a)   ​ (b)   ​ (c)  

• Protons
• Compounds
• Molecules
• Neutrons
• Electrons
• Elements

What is the center of an atom called, where protons and neutrons are tightly packed?

• Energy levels

• Electron clouds

• Nucleus

• Molecule

How many known elements are organized on the Periodic Table of Elements?

• 100

• 118

• 150

• 200

What is an element made up of?

(a)  

• A mixture of atoms

• Only one type of atom
• Two or more types of atoms

• Molecules

What is an example of an element?

• Water

• Gold

• Carbon dioxide

• Oxygen gas

What do atoms form when they join together by sharing or transferring electrons?

• Compounds

• Molecules

• Elements

• Nucleus

Which of the following is an example of a molecule made of different elements?

• O₂ (oxygen gas)

• CO₂ (carbon dioxide)

• N₂ (nitrogen gas)

• H₂ (hydrogen gas)

What happens when a molecule includes atoms of two or more different elements?

• It becomes an element

• It becomes a compound

• It becomes a molecule

• It becomes a nucleus

Which of the following is an example of a compound?

• O₂ (oxygen gas)

• H₂O (water)

• N₂ (nitrogen gas)

• H₂ (hydrogen gas)

What makes compounds unique compared to the elements that form them?

• They have the same properties as the elements

• They have unique properties different from the elements

• They are made of only one type of atom

• They are not chemically bonded