Supplementary 1

Question 1

What are physical changes and chemical reactions?

Answer 1

• A physical change is when a change in matter occurs but does not form new substances
• A chemical reaction is when a change in matter occurs which forms one or more new substances

Question 2

What are elements and compounds?

Answer 2

• Elements are only made up of one atom
• Compounds are made up of two or more atoms bonded together

Question 3

Which are the reactants and products in a chemical reaction?

Answer 3

• The substances that react with each other are the reactants
• The new substances formed by a reaction are called products

Question 4

What is a chemical reaction in terms of reactants, products, chemical bonds, and rearrangement of atoms?

Answer 4

A chemical reaction is a process in which one or more reactants are converted into one or more products. This starts when the chemical bonds are broken to allow the atoms to be rearranged in a new way. Once the atoms are rearranged, the chemical bonds are formed again to create new substances, the products.