Distribution of Electrons in Different Orbits (Shells)

Calculate the maximum number of electrons in $1$st, $2$nd, $3$rd and $4$th shells. 

How will you find out the maximum number of electrons in the main energy level? 

In iron, the differentiating electron enters into the orbital of a penultimate shell.

Do all the single electron species of various elements possess same energy for the electron in the ground state? Give reason.

An atom has electronic configuration $2, 8, 6$.

(a) What is the atomic number of this element ? 
(b) Which of the following elements would be similar in chemical properties?

      $\mathrm{N}\left(7\right), \mathrm{F}\left(9\right), \mathrm{P}\left(15\right), \mathrm{O}\left(8\right), \mathrm{Ar}\left(18\right)$

What is atomic configuration?

Why calcium electronic configuration is does not like $2, 8, 10$ but it is $2, 8, 8, 2$.

In which of the following compound the cation has pseudo inert gas configuration?

The maximum number of electrons present in a shell is given by the formula $2{\mathrm{n}}^{\mathrm{a}}$. Here, the value of a is _____. $(1, 2, 3)$

According to the Bohr Bury rule, the maximum number of electrons in a particular orbit is given by the formula $2{\mathrm{n}}^{\mathrm{a}}$. Here, the value of a will be _____. $(2, 4, 6)$

What is the electronic configuration of a hydrogen atom? $\left(1 / 0,1 / 1,1 / 2\right)$

Calculate the number of electrons, protons and neutrons in sodium atom. Write down the electronic configuration of sodium atom. (Given : atomic number of sodium is $11$ and mass number/atomic mass is $23$.)

Which energy shell is the nearest to the nucleus?

An ion ${\mathrm{A}}^{\mathrm{x}-}$ has atomic mass $35$ and atomic number $17$. Calculate the value of $\mathrm{x}$.

The electronic configuration of element A, B, C and D are $(2, 8, 1), (2, 8, 1), (2, 8, 6)$ and $(2, 8, 7)$ respectively. Which of them can make an ion with two negative charges?

The composition of two atomic particles are given:

Which element/elements do they represent? Also write down the electronic configuration. 

Compare the atoms of magnesium isotopes with respect to their electronic configurations. 

Why the filling of electrons starts in the $\mathrm{N}$-shell after $\mathrm{M}$-shell has acquired $8$ electrons?

Atomic number of chlorine is $17$ and mass number is $35$. Draw the structure of chlorine showing the composition of the nucleus as well as distribution of electrons in different shells. Also comment on its valency. 

Draw the electronic structures of sodium (proton number$=11$) and lithium (proton number$=3$). Compare the structures and state one similarity and one difference between them.