Electronic configuration

Q.

Write three necessary conditions for the formation of a covalent bond

Q. Question 3 (b)
Which element has the electronic configuration 2, 8, 2?

Q. Question 3 (d)
Which element has a total of two shells, with three electrons in its valence shell?

Q. The atomic number of silicon is

1. 20
2. 13
3. 12
4. 14

Q. Which of the following elements has the highest number of electrons in its valence shell?

1. 
   S
2. 
   P
3. 
   Ca
4. 
   Al

Q. Question 3 (e)
Which element has twice as many electrons in its second shell as in its first shell?

Q.

The number of valence electrons in ${\mathrm{O}}^{2-}$ ion is

1. $2$

2. $4$

3. $6$

4. $8$

Q. In general, how many electrons are there in the outermost shell of a metal?

1. 7
2. 1 to 3
3. 6 to 8
4. 0

Q.

Electron affinity depends on

1. Nuclear charge

2. Atomic size

3. Atomic number

4. Atomic size and nuclear charge both

Q.

What is the distribution of electrons in carbon and sodium atom?

Q.

What is the Valency of Magnesium with Atomic Number 12?

Q.

(a) Write down the electronic configuration of (i) magnesium atom, and (ii) magnesium ion.
(At. No. of Mg = 12 )
(b) Write down the electronic configuration of (i) sulphur atom and (ii) sulphur ion.
(At. No. of S = 16)

Q. Question 5 (a)
An atom has electronic configuration 2, 8, 7.
What is the atomic number of this element?

Q.

Complete and balance the following equations

(ⅰ ) ${\mathrm{N}}_2$ +${\mathrm{H}}_2$$\to$ $.....$

(ⅱ) ${\mathrm{NH}}_3$ +$$\begin{gathered} {\mathrm{Cl}}_2 \\ Excess \end{gathered}$$ $\to$$.....$

(ⅱⅰ) $\mathrm{PbO}$ + ${\mathrm{NH}}_3$ $\to$$.....+....+{\mathrm{H}}_2\mathrm{O}$

(ⅳ) ${\mathrm{NH}}_3$ + ${\mathrm{O}}_2$ $$\begin{gathered} \stackrel{\mathrm{pt}}{\to } \\ 800°\mathrm{C} \end{gathered}$$$.....+......$

Q.

The electronic configuration of titanium is 2, 8, 10, 2. How can we write its subshell electronic configuration?

Q.

Find the neutral atom in the periodic table which has the same number of electrons as $K^{+}$ and $C{l}^{-}$. What is this number?

Q. Non-metals form covalent chlorides because

1. they can give electrons to chlorine
2. they can share electrons with chlorine
3. they can give electrons to chlorine atoms to form chloride ions
4. they cannot share electrons with chlorine atoms

Q.

Which inert gas electron configuration do the Cl atoms in $C{l}_2$ molecule resemble? What is the electron configuration?

Q.

The atomic number of an element X is 12.
(a) What must an atom of X do to attain the nearest inert gas electron configuration?
(b) Which inert gas is nearest to X?

Q.

The correct electronic configuration for sodium ion is:

1. 2, 8, 1

2. 2, 8

3. 2, 8, 8, 1

4. 2, 8, 7

Q. A, B, C are three elements in which B is an inert gas other than helium. With this information complete the following table.

Element	Atomic number	No. of electrons in the valence shell	Group to which the element belongs
A B C	Z − 1 Z Z + 1	.... .... ....	.... .... ....

Also, explain the following:
(i) Electron affinity of element A is more than that of element C.
(ii) Ionization energy of element C is less than that of element A.
(iii) Electron affinity of B is zero.

Q.

(i) What is a lone pair of electrons?
(ii) Draw an electron dot diagram of a hydronium ion and label the lone pair of electrons.
(iii) Name a neutral covalent molecule which contains one lone pair of electrons.

Q.

In a neutral atom, the atomic number is equal to the number of ____.

Q. nt. Element with electronic configuration 1s2 is placed in (1) s-block (2) p-block (3) Group 3 (4) d-blockn

Q. Sodium tends to lose electron(s) to achieve nearest noble gas configuration.

1. two
2. one
3. three

Q.

$\mathrm{P}-\mathrm{P}$ bond present in_____.

1. ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_6$

2. ${\left({\mathrm{HPO}}_3\right)}_{\mathrm{n}}$

3. ${\mathrm{H}}_6{\mathrm{P}}_4{\mathrm{O}}_{13}$

4. None Of These

Q.

An __________ of oxygen does not exist independently.

Q.

Using a part of the periodic table given below answer the following questions:
(i) Na has physical properties similar to which elements and why?
(ii) Write the electronic configuration of N and P.
(iii) State one property common to fluorine and chlorine.

$$\begin{array}{ccccccccc}GroupPeriod& I& II& III& IV& V& VI& VII& Zero\\ 1& H& & & & & & & He\\ 2& Li& Be& B& C& N& O& F& Ne\\ 3& Na& Mg& Al& Si& P& S& Cl& Ar\\ 4& K& Ca& & & & & & \end{array}$$

Q.

Draw the electron dot structure of Sodium ($\mathrm{Na}$) and Oxygen ($\mathrm{O}$).

Q.

(a) Write down the electron arrangement in (i) a magnesium atom, and (ii) a chloring atom.
(b) How many electrons are there in the alence shell of (i) a magnesium atom, and (ii) a chlorine atom?
(c) Show the formation of magnesium chloride from magnesium and chlorine by the transfer of leectrons.
(d) State wheter magnesium chloride will conduct electricity or not. Give reason for your answer.
(e) Why are covalent compounds generally poor conductors of electricity?