I think your answer is D. However I’m not 100% sure.
Answer:
It will take 6.6 hours for 75% of the lead to decay.
Explanation:
The radioactive decay follows first order rate law
The half life and rate constant are related as

The rate law for first order reaction is
![time=\frac{1}{k}(ln[\frac{A_{0}}{A_{t}}]](https://tex.z-dn.net/?f=time%3D%5Cfrac%7B1%7D%7Bk%7D%28ln%5B%5Cfrac%7BA_%7B0%7D%7D%7BA_%7Bt%7D%7D%5D)
Where
A0 = initial concentration = 1 g
At= final concentration = 0.25 g (as 75% undergoes decay so 25% left]

They All are Living things.
Explanation:
ABC looks like the metamorphic rocks are more usable than other rocks
Answer:
0.017mole
0.0033M
Explanation:
Given parameters:
Formula of the compound:
Mg(ClO₃)₂
Mass of the sample = 3.24g
Unknown:
Number of moles of the sample = ?
Molarity = ?
Solution:
The number of moles of any substance is given as:
Number of moles =
Molar mass of Mg(ClO₃)₂ = 24 + 2[35.5 + 3(16)] = 191g/mol
Number of moles =
= 0.017mole
Molarity is the number of moles of a solute in a solution:
Molarity =
Volume given = 5.08L
Molarity =
= 0.0033M