Question

2) Fill in the blanks in the box below. 1)symbol______________ 2)atomic number________ 3) atomic mass _________ 4)valency_____________ 5) electron configuration_________​

Answer 1

Hydrogen

1) Symbol-H
2) atomic number-1
3) Atomic Mass-1.00784 u
4) Valency-1
5) Electron Configuration-1s1