Answer:
Explanation:
1. Add the atomic mass of all the elements.
39+55.8+12+14= 120.8
2.Divide atomic mass of potassium by total atomic mass

2. Multiply by 100
%32.3
Sorry, but where are the ‘items’?
Answer:
1.5x 10^24
Explanation:
for every 1 mol there are 6.02 x 10^23 molecules
2.5 mol x 6.02 x 10^23
-----------------
1 mol
Answer:
Explanation:
When going from top to bottom in any group of the periodic table, the atomic radius always tends to increase