Question

an atom contains 3 proton 3 electron and 4 nuetron find the mass no. and atomic no. and valency

Answer 1

heya folk

proton number = atomic number

so the element is lithium as it's proton number is 3

atomic mass number = number of protons + neutrons
= 4+3
= 7

valency is number of electrons in outer shell
e.c = 2,1
valency =1

Answer 2

Atomic no= no of electrons=3
mass no = no of proton+neutron=7
valency =1 as there are 3total electrons 2 in 1st shell and one in outermost shell