Timed the helium used to fill birthday balloons doesn’t come out of the air, but fromout of the ground. some of the gas might escape from the ground into theatmosphere, but the majority of it is trapped in earth’s crust. based on whatyou have learned in today’s lab, give a reasonable explanation for thepresence of helium gas in earth’s crust.

Helium is one of the lightest gas that is found to be stored in the interior of the earth's crust. This helium gas is formed from the constant radioactive decay process. During the time of radioactive decay, the radioactive elements  decays and give rise to the formation of alpha particles, which are positively charged. When a pair of electrons are combined with these alpha particles then it produces helium atom.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;