The number of protons in the nucleus of one atom of an element Y is 5. The symbol of ion formed by an atom of this element will be:

(a) $Y^{3-}$

(b) $Y^{2+}$

(c) $Y^{2-}$

(d) $Y^{3+}$

Q.

The atomic number of an element X is 16. The symbol of ion formed by an atom of the symbol of ion formed by an atom of this element will be:
(a) $X^{3-}$

(b) $X_{2+}$

(c) $X^{2-}$

(d) $X^{-}$

Q. The atom of an element X contains 17 protons, 17 electrons and 18 neutrons whereas the atom of an element Y contains 11 protons, 11 electrons and 12 neutrons.

(a) What type of ion will be formed by an atom of element X ? Write the symbol of ion formed.
(b) What will be the number of (i) protons (ii) electrons, and (iii) neutrons, in the ion formed from X ?
(c) What type of ion will be formed by an atom of element Y ? Write the symbol of ion formed.
(d) What will be the number of (i) protons (ii) electrons, and (iii) neutrons, in the ion formed from Y ?
(e) What is the atomic mass of (i) X, and (ii) Y ?
(f) What could the elements X and Y be ?

Q. If the number of protons in one atom of an element Y is 20, then the number of electrons in its ion Y²⁺ will be:
(a) 20
(b) 19
(c) 18
(d) 16

Q. An atom of element E contains 3 protons, 3 electrons and 4 neutrons :

(a) What is its atomic number?

(b) What is its mass number?

(c) Write the electronic configuration of the element E.

(d) State whether element E is a metal or non-metal. Why?

(e) What type of ion, cation or anion, will be formed by an atom of element E? Why?

(f) Write the symbol of the ion formed by an atom of element E.

(g) What could element X be?

Q.

The nucleus of an atom has 5 protons and 6 neutrons. What would be the (a) atomic number, (b) mass number, (c) the number of electrons, and (d) the number of valence electrons, per atom of this element?