The first model of an atom was given by:

The number of electrons in the atom of an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of an atom of this element?

The ion of an element has 3 positive charges. The mass number of atom of this element is 27 and the number of neutrons is 14. What is the number of electrons in the ion?

Which f the following statement is always correct?

From the symbol <ιμγωιδτη=∀31∀ηειγητ=∀32∀σρχ=∀Χη−4_Στρυχτυρε−οφ−Ατομ−1_φιλεσ/ιμαγε009.πνγ∀>, state:

(i) mass number of phosphorus,

(ii) atomic number of phosphorus, and

(iii) electron configuration of phosphorus.