Question

An ion M²+ has 2 electrons and 5 neutrons. The mass number and atomic number
of the corresponding atom are
a). 9,2. b). 5, 4. c). 4, 9. d). 9, 4.​

Answer 1

Answer:

(d)

Explanation:

In neutral start of element M , total number of protons = total number of electrons = 4

Mass Number = Number of protons+ Number of Neutrons = 4+5 = 9