The answer to this question would be: 2 half-lives
In this question, the mineral has a daughter to parent ratio of 3:1. That means, the amount of parent mass should be are 1/(3+1)= 1/4 of the total mass. For every half live, the parent mass would become 1/2. Then for 1/4, the number of half-lives should be:
1/2^x= 1/4
1/2^x= 1/2^2
x=2
Pretty sure its asteroids but double check to make sure.... hope this helps!
Answer:
The number of mole is 1.852moles
Explanation:
To calculate the number of mole, using the formula
n = m/Mm
n - number of mole
m - number of mass
Mm - number of molar mass
The molar mass of Re = 186.207
Then, n = 345g/ 186.207g/mol
n = 1.852mol
For Hydrocarbon combustion:
CₓHₐ + O₂ → xCO₂ + a/2 H₂O
Moles of CO₂ = 16.2 / 44 = 0.37
Moles of Carbon = 0.37
Moles of H₂O = 4.976 / 18 = 0.28
Moles of Hydrogen = 0.28 x 2 = 0.56
Molar ratio = C : H = 1 : 1.5
= 2 : 3
C₂H₃
Mass of empirical unit = 12 x 2 + 1 x 3
= 27
Mr = 54.09
Number of empirical units repeated: 54.09 / 27
= 2
Molecular formula = C₄H₆
