It is an example of physical change. The molecules are not changing, so it is not chemical, and a physical property is something that a physical thing has.
Atoms cannot physically get more compact (temperature lowering increases the space between atoms) At absolute zero, the atoms are as physically close together as allowed by the physical laws governing it.
At almost the opposite point on the Earth's surface, the "P" waves reappear. The shadow zone exists because the waves are refracted as they pass through the boundary between the mantle and the core and are diverted from their original paths.
Answer: 2) Electron X absorbs energy when it changes to a higher energy level.
Explanation:
The electrons in an atom exist in various energy levels. When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom. When an electron moves from a higher to a lower energy level, energy is released (often as light).
Ions are stable atoms of elements formed when original atoms loose or gain electrons to form stable configuration. Anions are negatively charged ions formed when atoms gain electrons while cations are the positively charged ions formed when atoms loose electrons. In this case a charge of +1 means an atom lost one electron to form a stable configuration. Therefore, the correct answer is A
