Question

the percentage of an element M is 60 in its oxide of molcular formula MO. the atomic mass of the element is?​

Answer 1

Percentage composition of an element = mass of element/ molar mass* 100

let mass of the element be X

mass of compound is X+16

=( X/X+16)*100= 60%

=X/X+16 = 3/5

=5X=3X+48

2X=48

X=24

The element with mass number 24 is magnesium

the atomic number of magnesium is 12