Question

explain why they become positive when they lose electrons and why they become negative when they gain electrons. why does this make sense?

Explanation:

Electrons are negatively charged particles. When an object loses electrons, it has fewer negative charges, so it has a net positive charge (since protons, which are positively charged, remain in the nucleus and their positive charge is now more dominant in terms of the overall charge balance). When an object gains electrons, it has more negative charges, resulting in a net negative charge. This makes sense because charge is conserved and the overall charge of an object is determined by the balance between the number of protons (positive) and electrons (negative) it has.

Answer:

An object becomes positive when it loses electrons because electrons are negatively charged. Losing them means there are fewer negative charges, so the object has a net positive charge (protons are positively charged and their number remains relatively constant in the nucleus). An object becomes negative when it gains electrons as it then has more negative charges. This makes sense as charge is conserved and the overall charge of an object is based on the balance between positive (protons) and negative (electrons) charges.