The oxidation state of a element in its uncombined state is

(a)

zero

(b)

+1

(c)

-1

(d)

none

The electronic configuration of Eu (Atomic no. 63) Gd (Atomic no. 64) and Tb (Atomic no. 65) are ____________

(a)

[Xe] 4f⁶ 5d¹ 6s², [Xe] 4f⁷ Sd¹ 6s² and [Xe] 4f⁸  5d¹ 6s²

(b)

[Xe] 4f⁷ , 6s², [Xe] 4f⁷ 5d¹ 6s² and [Xe] 4f⁹ 6s²

(c)

[Xe] 4f⁷ ,6s², [Xe] 4f⁸ 6s² and [Xe] 4f⁸ 5d¹ 6s²

(d)

[Xe] 4f⁶ 5d¹ 6s², [Xe] 4f⁷ 5d¹ 6s² and [Xe] 4f⁹ 6s²

Match the list I with List II and select the correct answer using. the code given below the lists.

List I		List II
A	A halogen	1	Cesium
B	An alkali metal	2	Germanium
C	A chalcogen	3	Iodine
D	A metalloid	4	Selenium

(a)

A	B	C	D
1	3	2	4

(b)

A	B	C	D
4	3	1	2

(c)

A	B	C	D
3	1	4	2

(d)

A	B	C	D
2	1	4	3

The most abundant element in the universe is _________.

(a)

aluminium

(b)

mica

(c)

dihydrogen

(d)

nitrogen

Potassium chloride is used as ____________

(a)

fertilizer

(b)

soft soap

(c)

electrochemical cells

(d)

all the above

At identical temperature and pressure, the rate of diffusion of hydrogen gas is 3\(\sqrt { 3 } \) times that of a hydrocarbon having molecular formula C_nH_2n-2. What is the value of n ?

(a)

8

(b)

4

(c)

3

(d)

1

Which of the following is the correct mathematical relation for Charles' law at constant pressure?

(a)

\(V\propto T\)

(b)

\(V\propto t\)

(c)

\(V\propto \frac{1}{T}\)

(d)

all of above

Statement-I: The pressure cooker takes more time for cooking at high altitude.
Statement-II: Air is subjected to Earth's gravitational force. The pressure of air gradually decreases from the surface of the Earth to higher altitude.

(a)

Statement-I and II are correct and Statement-II is the correct explanation of Statement-I

(b)

Statement-I and II are correct but Statement-II is not the correct explanation of Statement-I

(c)

Statement-I is wrong but Statement-II is correct

(d)

Statement-I is correct but Statement-II is wrong

Statement-I: Gases do not liquefy above their critical temperature, even on applying high pressure.
Statement-II: Above critical temperature, the molecular speed is high and intermolecular attractions cannot hold the molecules together because they escape because of high speed.

(a)

Statement-I and II are correct and Statement-II is the correct explanation of Statement-I

(b)

Statement-I and II are correct but Statement-Il is not the correct explanation of Statement-I

(c)

Statement-I is correct but Statement-Il is wrong

(d)

Statement-I is wrong but Statement-Il is correct

The heat absorbed at constant volume is equal to the system's change in:

(a)

enthalpy

(b)

entropy

(c)

internal energy

(d)

free energy