Electronic Configuration

Q. Name the gases used in (a) filling balloons​

Q. Identify the correct electronic configuration for ${\text{Mg}}^{2+}$ ion.

1. $1s^2$ $2s^2$ $2p^6$ $3s^2$ $3p^6$
2. $1s^2$ $2s^2$ $2p^6$ $3s^2$
3. $1s^2$ $2s^2$ $2p^6$
4. $1s^2$ $2s^2$ $2p^6$ $3s^2$ $3p^4$

Q.

Electronic configuration of Co (Cobalt)

Q.

An element has five electrons in the M-shell. The atomic number of the element is 15.

1. True
2. False

Q. Write the electronic configuration of an element whose mass number is 31 and atomic number is 15 . What is its valency?

Q. What is the electronic configuration of magnesium $\left({}_{12}^{24}Mg\right)$?

1. 2, 6, 3
2. 2, 8, 2
3. 2, 8, 3
4. 2, 6, 4

Q.

The electronic configuration of an atom is $2,8,3$. The number of valence electrons in the atom is:

1. 13

2. 10

3. 3

4. 8

Q.

Which of the following configuration of electrons represent sodium?

1. 2, 8, 4

2. 2, 8, 5

3. 2, 3

4. 2, 8, 1

Q. Is the following symbol of element incorrect? ​
Give the correct symbol.​
(i) Cobalt CO​
(ii) Carbon c
(iii) Aluminum AL
(iv) Helium He
(v) Sodium So

Q. An element A has an atomic number 6 and mass number 12, while element B has an electronic configuration of 2, 8, 2. Which of the following options is incorrect?

1. 
   Atomic number of ‘B’ is 12.
   
2. ‘B’ is a metal.
3. ‘A’ and ‘B’ are isotopes.
4. 
   Valency of ‘A’ is 4.
   

Q.

Arrange the following in ascending order of their valency

Boron, Beryllium and Lithium.

1. Boron, Beryllium and Lithium

2. Beryllium, Boron and Lithium

3. Lithium, Beryllium and Boron.

4. None of these

Q.

Give an example where symbol is derived from two letters of the name of element.

Q.

Q. Find out the valency of the atoms represented by the figures
(a) ​

(b)

Q. Given below are the atomic number of elements. What will be the no. of valence electrons in each of them respectively?
$$\begin{array}{cc}\text{Element}& \text{Atomic no.}\\ \text{Carbon}& \text{6}\\ \text{Nitrogen}& \text{7}\\ \text{Oxygen}& \text{8}\end{array}$$

1. 4, 2, 3
2. 4, 5, 6
3. 4, 3, 2
4. 6, 7, 8

Q. (b) Comment on the
(iii) physical state of group $17$ elements.

Q.

Which of the following is the correct IUPAC symbol for the element Cobalt?

1. C

2. CO

3. Co

4. Cb

Q.

What is the electronic configuration of an atom that has a proton number of 5 and a mass number of 11?

Q.

15. Give one word for the following.

iii. The scientific representation of an atom of an element.

Q. An element has 5 electrons in its outermost shell, what type of ion it will be formed? Also provide the charge on the ion. [2 marks]

Q. Which of the following symbol represents chlorine?

1. C
2. Cr
3. Cl
4. Co

Q.

Define the following terms with examples: Divalent

Q.

State the followings as true (T) or false (F):

(a) The electronic configuration of magnesium is 2, 8, 2. So its valency is 2.
(b) Atom attains stability when it achieves the noble gas configuration.
(c) Number of electrons in an atom = Mass number​

Q. If the electronic configuration of boron is 2, 3 then how many electrons are there in outermost shell of gallium?

1. 3
2. 1
3. 2
4. 4

Q. Given below are the atomic number of elements. What will be the no. of valence electrons in each of them respectively?
$$\begin{array}{cc}\text{Element}& \text{Atomic no.}\\ \text{Carbon}& \text{6}\\ \text{Nitrogen}& \text{7}\\ \text{Oxygen}& \text{8}\end{array}$$

1. 4, 2, 3
2. 4, 5, 6
3. 4, 3, 2
4. 6, 7, 8

Q. The number of subshells and orbitals possible for the principal quantum number 5 is

1. 5, 5
2. 4, 16
3. 5, 25
4. 25, 5

Q.

Give certain characteristics of gravitational force.

Q. A sodium atom contains a total number of 11 electrons. The valency of sodium atom is __

1. 4
2. 3
3. 1
4. 2

Q. Hydrogen molecule consists of ______ covalent bond(s).

1. zero
2. three
3. one
4. two

Q. Which of the following is the correct electronic configuration of sodium atom?

1. 2, 8, 2
2. 2, 5, 2
3. 2, 8, 1
4. 2, 2, 2