Sagot :
(0.250 mol K2CO3)(2 mol K/1 mol K2CO3)(6.022 x 10^23 atoms K/1 mol K) = 3.01 x 10^23 atoms Hope this helps!
Are the numbers meant to be subscript? Assuming they are, there is one carbon, two potassium, and three oxygen.
Answering d), ten potassium, five carbon, and fifteen oxygen
Answering d), ten potassium, five carbon, and fifteen oxygen