My main reason would be momentum – it depends on the mass as
well as the speed of the colliding objects. For example if two sedans
travelling in a low speed bump each other, then probably the damage would be
minimal scratches. However, if a high speed car crashes unto a heavy truck also
travelling fast, then the result would be catastrophic.
Electrons are the negatively charged particles of atom.
An atom consists of a positively charged nucleus surrounded by one or more negatively charged particles called electrons
To find the ionic charge of an element you'll need to consult your Periodic Table. On the Periodic Table metals (found on the left of the table) will be positive. Non-metals (found on the right) will be negative.