Answer:
<h2>0.5 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula

where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have

We have the final answer as
<h3>0.5 moles </h3>
Hope this helps you
Answer is "C"
alpha decay is an emission of ₂⁴He nucleus. If an element undergoes an alpha decay, the mass of the daughter nucleus formed is reduced by 4 compared to mass of parent atom and atomic number is reduced by 2 compared to atomic number of parent atom.
Explanation:
So first find out the moles. The percentage is out of 100 so just convert the percentage into mass by just changing the sign.
Ga = 55g/69.7 = 0.789 moles
F=45g/19 = 2.37 moles
Then divide by smallest value to find out the formula
Ga=0.789÷0.789= 1
F=2.37÷0.789 = 3
GaF3
hope this helps:)