Question

Given the following Unknown atoms with their respective atomic numbers,
X; Atomic number 19,
Y; Atomic number 15,
a. Deduce the identities of the elements X and Y.
b. What are the mass numbers of the two elements X and Y?
c. Calculate the number of Neutrons in the respective elements X and Y
d. Deduce the number of electrons in the respective elements X and Y
e. Give the electronic configurations of the two elements