Question

calculate the molecular mass
pls help me guy's​

Answer 1

Well, you should know the atomic mass of first 20 elements:

H-1

He-4

Li-7

Be-9

B-11

C-12

N-14

O-16

F-19

Ne-20

Na-23

Mg-24

Al-27

Si-28

P-31

S-32

Cl-35.5

Ar-40

K-39

Ca-40

1) 40+2(35.5)

=111

2) 2(39)+32+4(16)

=174

3) 39+14+3(16)

=101

4) 40+12+3(16)

=100

5) 14+3(1)

=17

6) 40+32+4(16)+[2(1)+16]/2

=145

7) 40+32+4(16)+2[2(1)+16]

=172

8) 23+14+3(16)

=85

9) 1+14+3(16)

=63

$\huge\green{Hope\: this \: helps \: you}$