Represent different types of periodic properties in the periodic table.

State whether the following statements are true or false:
$(i)$ As the atomic number increases in a period,the nuclear charge increases,therefore the ionization enthalpy increases.
$(ii)$ As the metallic character of elements increases,the atomic radius generally increases.
$(iii)$ $Mn$ $(Z = 25)$ is a transition element. Although it is a $3d$-orbital element,its position in the periodic table is in the $4^{th}$ period.

The isoelectronic set of ions is

Which of the following statements are correct?
$A.$ The process of the addition of an electron to a neutral gaseous atom is always exothermic.
$B.$ The process of removing an electron from an isolated gaseous atom is always endothermic.
$C.$ The $1^{st}$ ionization energy of boron is less than that of beryllium.
$D.$ The electronegativity of $C$ is $2.5$ in $CH_4$ and $CCl_4$.
$E.$ $Li$ is the most electropositive among elements of group $I$.
Choose the correct answer from the options given below:

Which of the following orders is incorrect?

How many of the following statements are correct?
$(a)$ 'He' is the second most abundant element in the universe.
$(b)$ The symbol for the element with atomic number $110$ is Ds.
$(c)$ Osmium has the highest density among all elements.
$(d)$ Francium is the most electropositive element in the periodic table.