The overall charge of an atom is positive if the number of electrons is less than the number of protons. Electrons are negatively charged particles while protons are positively charged particles. If there are less electrons as compared to the number of protons in an atom, then naturally the overall charge of the atom would be positive since there are excess protons. Another case would be that the overall charge of an atom is negative if the number of electrons is greater than the number of protons. An atom having more electrons than the number of the protons present would lead to a negative value of the charge since there are excess electrons.
The correct answer is c. Temperature is the average kinetic energy of a sample so if two samples have the same temperature they will also have the same average kinetic energy. I hope this helps. Let me know if anything is unclear.
The correct answer is A. O^2-
Gravity forces earth to move around the sun so A