Answer:
Can I get my 50 points now?
Explanation:
The helium is formed during the natural radioactive decay of elements such as uranium and thorium. These heavy elements were formed before the earth but they are not stable and very slowly, they decay. One mode of decay for uranium is to emit an alpha-particle.
Answer:
1. Percentage by weight = 0.5023 = 50.23 %
2. molar fraction =0.153
Explanation:
We know that
Molar mass of HClO4 = 100.46 g/mol
So the mass of 5 Moles= 5 x 100.46
Mass (m)= 5 x 100.46 = 502.3 g
Lets assume that aqueous solution of HClO4 and the density of solution is equal to density of water.
Given that concentration HClO4 is 5 M it means that it have 5 moles of HClO4 in 1000 ml.
We know that
Mass = density x volume
Mass of 1000 ml solution = 1 x 1000 =1000 ( density = 1 gm/ml)
m'=1000 g
1.
Percentage by weight = 502.3 /1000
Percentage by weight = 0.5023 = 50.23 %
2.
We know that
molar mass of water = 18 g/mol
mass of water in 1000 ml = 1000 - 502.3 g=497.9 g
So moles of water = 497.7 /18 mole
moles of water = 27.65 moles
So molar fraction = 5/(5+27.65)
molar fraction =0.153
Answer:
2.28
Explanation:
HCl(l) ===> H+ + cl-
HCl is a very strong acid. Almost all of it will decompose to the right. That means the concentration of H+ is 0.00530
pH = - log [H+]
pH = - log[0.00530]
pH = - - 2.2757
pH = 2.2757
Rounded this 2.28
Because they have a full outer shell and they are both noble gases...Because the outer shell has attained stable electronics configuration of octate rule this it is with noble gas as helium.
Hope I helped!
