Which of the following figures do not represent Bohr's model of an atom correctly?

$(a)$ How many neutrons are present in $C-14$ isotope of carbon?
$(b)$ How many protons does $He^{2+}$ ion possess?
$(c)$ How many maximum electrons can be filled in the $3^{rd}$ orbit of an atom?
$(d)$ How many electrons does $He^{2+}$ ion possess?

Elements with valency $1$ are

State three rules suggested by Bohr and Bury for the distribution of electrons into different orbits (shells) of an atom.

Study the table given below and answer the questions that follow:

Particle	Electrons	Protons	Neutrons
$M$	$2$	$3$	$4$
$N$	$10$	$9$	$10$
$O$	$8$	$8$	$8$
$P$	$8$	$8$	$10$

$(a)$ Write the mass numbers of particles $M, N, O$ and $P$.
$(b)$ Select a cation and an anion from the above table.

$A, B$ and $C$ are three metals with atomic numbers $4, 11$ and $13$ respectively. Arrange the metals in the increasing order of their valency.