Assertion: The atomic masses of most of the elements. are in the fraction. 
Reason:  The atomic mass represents the ratio of the average mass of the atom to one avogram.
Codes:
(a) Both assertion and reason are correct and the reason is the correct explanation for assertion
(b) Both assertion and reason are correct but the reason is not the correct explanation for an assertion
(c) Assertion is true but reason are false
(d) Both assertion and reason are false

(a)

Both assertion and reason are correct and the reason is the correct explanation for assertion

(b)

Both assertion and reason are correct but the reason is not the correct explanation for an assertion

(c)

Assertion is true but reason are false

(d)

Both assertion and reason are false

One mole of CO₂ contains __________.

(a)

6.023 x 10²³atoms of C

(b)

6.0²³ x 10²³atoms of O

(c)

18.1 x 10²³molecules of CO₂

(d)

3g atoms of CO₂

Which of the following electronic configuration represent the element in ground state?

(a)

1s²2s¹2p¹

(b)

1s²2s²2p¹

(c)

1s²2s¹2p_x¹2p_y¹2p_z¹

(d)

1s²2s²2p⁶3s²3p_x¹3p_y¹3p_z¹3d¹

J. J. Thomson's cathode ray experiment revealed that atoms consist of _____________

(a)

electrons

(b)

protons

(c)

neutrons

(d)

photons

The maximum number of electrons that can be accommodated in N shell is_____________

(a)

8

(b)

18

(c)

32

(d)

36

The idea of stationary orbits was first given by_________.

(a)

Rutherford

(b)

J.J. Thomson

(c)

Niels Bohr

(d)

Max Planck

The following tame shows the successive molar ionisation energy (kJ mol^-1) of five elements A to E. Which of two elements are most likely to be in the same group of the periodic table

Element	Ionisation Energy (K mol-1)
		1st	2nd	3rd	4th
	A	2080	4000	6100	9400
B	500	4600	6900	9500
C	740	1500	7700	10500
D	580	1800	2700	11600
E	420	3100	4400	5900

(a)

C and D

(b)

D and E

(c)

B and D

(d)

B and E

The chemical symbol of carbon and cobalt are______

(a)

Ca and CO

(b)

Ca and Cl

(c)

C and CO

(d)

Cr and Cb

Among halogens, the correct order of amount of energy released in electron gain is ________

(a)

F>CI>Br>I

(b)

F

(c)

FBr>I

(d)

FI

Statement- I: Ionization enthalpy of Be is greater than that of B.
Statement- II: The nuclear charge of B is greater than that of Be.

(a)

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

(b)

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

(c)

Statement-I is correct but statement-II is wrong.

(d)

Statement-I is wrong but statement-II is correct.

The electronic configuration of the atom having maximum difference in first and second ionisation energies is _________

(a)

1s², 2s², 2p⁶, 3s¹

(b)

1s², 2s², 2p⁶, 3s²

(c)

1s², 2s², 2p⁶, 3s², 3s², 3p⁶, 4s¹

(d)

1s², 2s², 2p⁶, 3s², 3p¹

Hydrogen burns in air with a - flame.

(a)

light blusish

(b)

yellow

(c)

green

(d)

none of these

In which of the following compounds does hydrogen has an oxidation state of -1?

(a)

CH₄

(b)

NH₃

(c)

HCl

(d)

CaH₂

Heavy water is __________

(a)

 De-mineralized water

(b)

De-ionized water

(c)

ordinary water containing dissolved salts of heavy metals.

(d)

The compound of heavier isotope of hydrogen with oxygen.

A example of covalent hydride is ____________

(a)

CaH₂

(b)

CH₄

(c)

TiH

(d)

all the above

Compounds of alkaline earth metals are less soluble in water than the corresponding alkali metals salts due to ________

(a)

their increased covalent character

(b)

high lattice energy

(c)

their high ionization energy

(d)

none of the above

Which one of the following alkaline earth metal is not readily attacked by acids?

(a)

Magnesium

(b)

Calcium

(c)

Beryllium

(d)

Strontium

Which one of the following is used in toothpaste, shampoo and hair products?

(a)

Plaster of paris

(b)

Limestone

(c)

Quick lime

(d)

Gypsum

Which one of the following metal act as co-factor in phosphate transfer of ATP by enzymes?

(a)

Calcium

(b)

Beryllium

(c)

Magnesium

(d)

Sodium

Which of the following gas is present maximum in atmospheric air?

(a)

O₂

(b)

N₂

(c)

H₂

(d)

radon

Heat of combustion of methane is____________ KJ/mol.

(a)

-87.78

(b)

+87.78

(c)

-394.55

(d)

+394.55

The condition for standard free energy is _______

(a)

298 K, 1 atm

(b)

273 K, 1 atm

(c)

298⁰ C, 5 atm

(d)

25 K, 1atm

For the formation of Two moles of SO₃(g) from SO₂ and O₂, the equilibrium constant is K₁. The equilibrium constant for the dissociation of one mole of SO₃ into SO₂ and O₂ is __________

(a)

\(1/K_1\)

(b)

\(K_1^2\)

(c)

\(({1\over K_1})^{1/2}\)

(d)

\({K_1\over 2}\)

Assertion: Oxygen molecule is paramagnetic.
Reason: It has two unpaired electron in its bonding molecular orbital.
a) both assertion and reason are true and reason is the correct explanation of assertion
b) both assertion and reason are true but reason is not the correct explanation of assertion
c) assertion is true but reason is false
d) Both assertion and reason are false

(a)

both assertion and reason are true and reason is the correct explanation of assertion

(b)

both assertion and reason are true but reason is not the correct explanation of assertion

(c)

assertion is true but reason is false

(d)

Both assertion and reason are false

The name of C₂F₄Cl₂ is ___________

(a)

Freon – 112

(b)

Freon – 113

(c)

Freon – 114

(d)

Freon – 115