It is a physical change because the reaction can easily be reversed and no heat is involved.
It is a chemical change. The reaction of sodium metal with chlorine gas is a highly energetic reaction that is a type of fire!
This is a chemical change.
dawd
bg
A physical change
Physical change of the paint, not the door.
the difference between a physical change and a chemical change is that a physical change is usually reversible whilst a chemical change is not reversible.
Physical... chemically, it's still the same substance,
A physical change is reversible, a chemical change is not.
chemical
chemical
this is a chemical change.
It is a physical change because the chemical composition has not changed.
this is a chemical change.
chemical because it involves stuff like chlorine
It is a chemical change.2NaCl --> 2Na + Cl2
Physical Change.
It is a chemical change, where a chemical such as oxygen or chlorine combines with a metal, forming an oxide or chloride of that metal.
When you combust hydrogen in air, the hydrogen will combine with oxygen to form water. Therefore, the hydrogen and oxygen are undergoing a chemical change to become bonded together producing H2O: 2H2 + O2 → 2H2O + Heat
NaCl itself is not a change. If you mean the formation of it from sodium ad chlorine, however, it is a chemical change.
Formation of NaCl from chlorine and sodium is a chemical process.