Avogadro's number is 1 mol = 6.02 * 10^23 elements
It means that 1 mol of atoms is 6.02 * 10^23 atoms
1 mol of atoms = 6.02 * 10^23 atoms
From there, if you divide both sides by 1 mol of atoms, you get
1 = 6.02 * 10^23 atoms / 1 mol of atoms.
That means, that to pass from a number of moles of atoms to number of atoms you have to multipby by the conversion factor
6.02*10^23 atoms Al/ 1 mol Al
That is the second option of the list.
Answer:
0.015 M
Explanation:
For a first order reaction;
ln[A] =ln[A]o - kt
[A] = final concentration
[A]o =initial concentration
k= rate constant
t= time taken
ln[A] =ln[A]o - kt
ln[A] = ln(0.0500) - 6.7 x 10-4 (30 × 60)
ln[A] = -2.9957 - 1.206
ln[A] = -4.202
e^ln[A] = e^(-4.202)
A= 0.015 M
<span>A small proportion of helium in the crust is helium that was trapped in the Earth when the Earth formed and has not yet escaped. Most helium on Earth, however, forms as a result of alpha decay of uranium and thorium. The emitted alpha particles, once they grab a couple of stray electrons, become helium atoms and can accumulate in gas reservoirs along with things such as methane.</span>
