Answer:
2
Explanation:
Pb(NO3)2 + 2NaI 2NaNO3 + PbI2
Convalent Bond energy is low
If a material mixes readily with water it is describe as HYDROPHILIC. Hydrophilic substances are water loving molecules, there reaction with water is favorable in term of thermodynamics. This type of substance are usually charged and often have ability to get involve in hydrogen bonding.
C. mass is protons and neutrons. Both are in the nucleus