How are positively and negatively charged ions formed?

Explanation of the solution to the problem: as a result of a chemical reaction, as well as under the influence of external factors (for example, temperature), an atom is able to accept or give up electrons that are at its external electronic level. If an atom donates electrons, then it has an excess of protons (positive particles), since initially the number of protons in the atom is equal to the number of electrons, which means that the ion becomes positively charged (cation). And if an atom accepts a certain amount of electrons, then it has an excess of electrons, and since they are negatively charged, the ion also begins to have a negative charge (anion).