Physical or chemical change

Today in science we did a experiment on zinc oxide  

 I think there will be possibly be sparks because of the reaction of heat to chemicals. It could turn yellow. 

1. Sample of zno - zinc oxide 
2. Heat source - heat plate
3. Scales
4. Heat proof container 
5. Tongs
6. Heat proof mat 

Get sample of zno in an evaporating dish 

Weigh the zno + container - record weigh 

Heat container + zno on hot plate

Observe any changes - use phone for before and after photos or video 

Take off heat and put on heat proof mat

Let cool - observe - photos

Reweigh 

Conclusion: 

it turned slightly yellow once put on heat plate and left there for a while, after a while the colour went back to white there for the change was physical. after we put the zno in the evaporating dish we the weighed it, which weighed 37 once we took it off the heat plate we weighed it again which hadn't changed and still weighs 37