Chemical Reactions

Which of the following models best demonstrates a balanced chemical equation?

• F
• G
• H
• J

Is melting ice a chemical or physical change?

• chemical
• physical

Is glass breaking a chemical or phyiscal change?

• chemical
• physical

Is melting butter for popcorn a chemical or physical change?

• chemical
• physical

What is the left part of a chemical equation called?
H_{2 +} O → H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Is this balanced?
2HgO → 2Hg + O₂

• Yes
• No

Is this balanced?
Al + O₂ → 2Al₂O₃

• Yes
• No

Which of the following equations demonstrates an actual chemical reaction that forms a new substance? (HINT: it must follow the Law of Conservation of Mass)

• A
• B
• C
• D

Which is an example of a chemical reaction?

• paper cut into small pieces
• chocolate melting in a pan
• flour and sugar mixed in a bowl
• cookies baking in an oven

How many atoms in all are in a molecule of serotonin?

C₁₀H₁₂N₂O

• 22
• 24
• 25
• 4