The correct letter to your answer would be A
Answer:
4.21
Explanation:
use Avogadro's number
6.023 x 10^23
multiply this by 7 because you want to find 7 moles :
6.023 x 10^23 x 7 = 4.21
Answer:
Krypton
Explanation:
When Selenium forms an ion, it is trying to become krypton which is a noble gas.
Selenium belongs to the oxygen group on the periodic table. In this group, the atoms prefers to gain two electrons to complete their octet. When selenium gains two electrons, its octet is complete.
This will make the atom resemble krypton on the periodic table of elements.
This structure which is an octet confers a special stability on the element.
Answer: Percent recovery is 47.34 %
Explanation:
Percent yield is defined as the ratio of experimental yiled to theoretical yield in terms of percentage.

Putting in the values we get:

Therefore, the percent recovery is 47.34 %