NaCl is a compound formed by a chemical reaction between Na (Sodium) and Cl (Chlorine). Sodium is an alkai metal in Group One of the Periodic Table, and it is very reactive. All alkai metals react violently with water and they are often found combined in nature because they are that reactive. Chlorine is a halogen in Group 17 of the Periodic Table and they are very reactive.
This question is asking: Why does gravity occur? why will your notebook get pulled towards you?
Answer:
The number of molecules displaced in a vibration makes the amplitude of a sound.
Answer:1. Transparent
2. Transparent
3. Opaque
Explanation: In a transparent medium light can pass through. For opaque objects it does not allow to pass through instead it is reflected back.