The reaction of 4.8 g sulfur and 5.4 g aluminum yields 4.5 g
Al2S3 in the reaction below:
35 + 2A1 - Al2S3
Determine the percent yield of Al2S3. (Molar mass of S = 32
g/mol, molar mass of Al = 27 g/mol)
Enter the answer

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom. 

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts

What are the activitys?   sorry if this took your points : (