I have the same question too!!!Dang I thought I would get a answer I just guessed
Answer:
The reaction in which heat is absorbed from the surrounding is called endothermic reaction.
so
I think it's answer is 2nd option.
Adding perchloric acid to water would cause it's conductivity to increase.
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
Answer:
zygote
Explanation:
Zyg is the shorten term for zygote.