What charges do they have?
Every object has an atom. There are protons, electrons, and neutron. As you can see from above picture Proton has positive charge, electron has negative charge, and neutron doesn't have a charge (neutral). And protons and neutrons don't move at all in an atom. Only electrons move.
Negative and positive charged
Electron can move freely, so an atom can lose or gain electron. When atom loses electrons, there will be more protons than electrons. When atom gains electrons, there will be more electrons than protons. As I said before, proton has positive charge and electron has negative charge. So when there are more protons, it is positive charged, and when there are more electrons, it is negative charged.
Reaction between negative, positive and neutral object
-Negative & Negative = repel
-Negative & Positive = attract
-Negative & Neutral = they actually don't repel, but neutral tries to repel
-Positive & Positive = repel
-Positive & Neutral = they actually don't attract, but neutral tries to attract
-Neutral & Neutral = nothing
When distance between two objects are closer, charge will be stronger and distance between two objects are further, charge will be weaker.
