Explanation:
Hi for this one u just need to remember and use the equation.

then u find mr of potassium which is 39.1.
then u do

you get the answer as 0.5115 write ur answer to 3 significant figures which will be 0.512 moles .
hope this helps :)
Answer:
it's a D answer if it's wrong please can you understand my question please
The answer is 6.4109 grams
Answer:
Mg
Explanation:
The element in the third row with two 3s electrons and no 3p electrons is magnesium — Mg.