Isotopes are atoms of the same element that have different masses. The relative atomic mass (am) is a weighted average that takes into account the abundance of each isotope. We can calculate the relative atomic mass using the following expression.

where,
- abi: percent abundance of each isotope
For Gallium,
[1]
where "x" and "y" are the unknown abundances.
We also know that the sum of both abundances must be 100%.
x + y = 100
y = 100 - x [2]
If we replace [2] in [1], we get

Then, in [2]
y = 100 - x = 100 - 20.5 = 79.5
In conclusion, Ga-69 has an abundance of 20.5% and Ga-71 has an abundance of 79.5%.
You can learn more about isotopes in: brainly.com/question/21536220?referrer=searchResults
Answer:
the stem, but if its more specific xylem cells
Answer:
In the option(A) moles of HCl left are 0.100 moles which is wrong, making the option incorrect.
Explanation:

Moles of HCl = n
Molarity of HCl = 1.0M
Volume of HCl solution = 30.0 mL = 0.030 L (1 mL = 0.001L)


Moles of Fe = 
According to recation , 1mol of Fe reacts with 2 mol HCl. Then 0.01 mole of Fe will recat with :
of HCl
This means that HCl uis in excess , hence excessive reagent.
Moles of HCl left unreacted :
= 0.030 mol - 0.020 mol = 0.010 mol
But in the option moles of HCl left are 0.100 moles which is wrong, making the option incorrect.
Answer:J , the answer is super giants