What do these two changes have in common?
sewing an apron
snowflakes forming in a cloud
Both are only physical changes. Both are chemical changes. Both are caused by cooling. Both are caused by heating.
Step 1: Think about each change.
Sewing an apron is a physical change. The fabric and thread that make up the apron get a new shape, but the type of matter in each of them does not change.
Snowflakes forming in a cloud is a change of state. So, it is a physical change. Liquid water freezes and becomes solid, but it is still made of water. A different type of matter is not formed.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are physical changes. No new matter is created.
Both are chemical changes.
Both changes are physical changes. They are not chemical changes.
Both are caused by heating.
Neither change is caused by heating.
Both are caused by cooling.
A snowflake begins to form when a tiny drop of liquid water in a cloud freezes. This is caused by cooling. But sewing an apron is not.