An atom does not easily lose or gain electrons if is has an equal number of protons and electrons. The charges inside the atom cancel each other, making it neutral.
This is a physical change. There is nothing that changes the components of either the diamond or the glass when the diamond is used to scratch glass.
That is a true statement.
212 kJ of energy must be added. hope this help ya
Take a piece of paper and cut it in half (anywhere will do) and you will have two pieces of paper - and your original piece of paper has changed shape.