Best Answer
1 mole of a substance contains 6.022x10^23 "units" of that substance.
So 0.187 mol of Na+ is 1.13x10^23 ions (6.022x10^23 x 0.187).
A sample of a compound contains 60.0 g C and 5.05 g H.
divide by molar mass of C(12) and H(1) to get molar ratio
C: 60/12=5 and H: 5/1=5
so C:H=5:5=1:1
total molar mass=78
divide by 1C+1H to find the formula: 78/(12+1)=78/13=6
compound is C6H6
For radioactive decay, we can relate current amount, initial amount, decay constant and time using:
N = No x exp(-λt)
Half-life = ln(2)/λ
λ = ln(2) / 5730
N/No = 80% = 0.8
0.8 = exp( -ln(2)/5730 x t)
t = 1844 years
I'm not so sure but I would say Answer Choice B
Protons .because electron has negative charge and proton has positive charge.
