An atom has 18 electrons and 22 neutrons. Its mass number is: MCQ with Answer and Explanation

Explanation:
Nuclear fission is a reaction in which the nucleus of a heavy atom (like Uranium-235 or Plutonium-239) splits into two or smaller, lighter nuclei when bombarded by a neutron, releasing a massive amount of energy and more neutrons, potentially causing a chain reaction.

Explanation:
H₂O₂ acts as an oxidizing agent, breaking down colored organic compounds into colorless products. It bleaches hair, textiles, and paper. It also acts as a disinfectant. It decomposes to water and oxygen, leaving no harmful residue, making it environmentally friendly.

Explanation:
Sodium has the electronic configuration [Ne]3s1. After losing one electron to form Na+, it achieves a highly stable noble gas configuration ([Ne]). Removing a second electron from this stable core requires an exceptionally large amount of energy. Thus, sodium has the highest second ionization energy among these elements.