Metals of Group 1 donate 1 electron from its ns orbital to form ionic bond, where n is the no. of its outermost shell.
Metals of Group 2<span> donate 2 electrons from its ns orbital to form ionic bond, where n is the no. </span>of its <span>outermost shell. </span>
Answer: Total pressure inside of a vessel is 0.908 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual partial pressures. exerted by each gas alone.

= partial pressure of nitrogen = 0.256 atm
= partial pressure of helium = 203 mm Hg = 0.267 atm (760mmHg=1atm)
= partial pressure of hydrogen =39.0 kPa = 0.385 atm (1kPa=0.00987 atm)
Thus 
=0.256atm+0.267atm+0.385atm =0.908atm
Thus total pressure (in atm) inside of a vessel is 0.908
I would say B.
Explanation: Peer review improves the quality of research papers.
Answer:
if a mixture of a given percentage or ratio strength is diluted to twice its original quantity, its active ingredient will be contained in twice as many parts of the whole, and its strength therefore will be reduced by one-half