Answer:
Option C. Gain 1 electron
Explanation:
Valence electron(s) are the electron(s) located on the outermost shell of an atom. Valency is simply defined as the combining power of an atom.
Chlorine (Cl) atom has 7 valence electron. This implies that Cl needs just one electron to complete it's octet configuration. It will be difficult for Cl to lose any of it's valence electron(s). Cl can either gain or share 1 electron to become stable.
Thus, considering the options given in the question above, option C gives the correct answer to the question.
Answer:
0.91 atm is the partial pressure of just hydrogen gas.
Explanation:
Vapor pressure of water , p= 0.0313 atm
Partial pressure of hydrogen gas = 
Total pressure of the water vapors and hydrogen gas = P = 715 Torr
1 atm = 715 Torr

According Dalton's law of partial pressure:



0.91 atm is the partial pressure of just hydrogen gas.
Answer:
It could be because of a physical change.
Explanation:
A physical change affects a substance's physical properties, and a chemical change affects its chemical properties.