Question

Q1.the divalent cation of an atom contains 10 electrons .if mass number of an element is 24 find the number of electrons, protons and neutrons in the ion and atomic number of the element.
Q2. the monovalent anion of an atom has 18 electrons mass number is 35 find the number of electrons, protons and neutrons and atomic number
Q3.the divalent cation of an element contains completely filled L shell .find the number of electrons ,protons and neutrons in the cation if its mass number is 24
q4.the monovalent anion of an element completely filled L shell find atomic number, electronic configuration, electrons, protons and neutrons of mass number is 19
please tell these all 4​

Answer 1

Solution :

Atomic number = 19

Number of protons = Number of electrons = 19

Mass number = Number of protons + Number of neutrons

39 = 19 + N

N = 20

Electronic configuration

19 = (2, 8, 8, 1)

Electrons in K shell (1st) = 2

Electrons in L shell (2nd) = 8

Electrons in M shell (3rd) = 8

Electrons in N shell (4th) = 1

Valence electrons is the number of electrons in the outer shell, i.e. 1 in this atom.