Question

element A (mass =20g) and element B (mass =30g) form a compound with molecular formula unit A2B2 . what is its formula mass/?

Answer 1

Formula mass = Sum of masses of elements

Here $A_{2}B _ { 2} = 2 A + 2B$

So given mass of A = 20 g

Mass of B = 30g

Finally formula mass = $2*20+ 2*30 = 40+60= 100$

#Praneeth