sodium metal is insoluble in ether.

Question

sodium metal dissolves in water to produce a gas.
The copper bottom on a frying pan turns black after several heatings.
Are these physical or chemical changes..

Answer 1

Sodium metal is insoluble in ether - No change but technically you can call the sodium in ether an insoluble mixture and therefore a physical change.

Sodium metal dissolves in water to produce a gas - You get a chemical change happening here because the sodium reacts with the water.

The copper bottom on a frying pan turns black after several heatings - That's a chemical reaction forming copper (II) oxide so it's a chemical change.

Answer 2

physical or chemical property
sodium metal fohrmhs an oxide when heated with oxygen?