Explore topic-wise InterviewSolutions in Current Affairs.

Atomicity: The number of atoms constituting a molecule is known as its atomicity.

Sulphur molecule (S₈): Atomicity is 8

Ozone molecule (O₃): Atomicity is 3

Phosphorus molecule (P₄): Atomicity is 4

Methane molecule (CH₄): Atomicity is 5

Thus, option C is correct.

Chemical formulae 

It is the symbolic representation of the composition of a compound. 

Characteristics of chemical formulae 

• The valencies or charges on ion must balance. 

• When a compound is formed of metal and non-metal, symbol of metal comes first. E.g., CaO, NaCl, CuO. 

• When polyatomic ions are used, the ions are enclosed in brackets before writing the number to show the ratio. E.g., Ca(OH)₂, (NH₄)₂SO₄

Rules for writing chemical formulae 

(i) We first write symbols of elements which form compound. 

(ii) Below the symbol of each element, we should write their valency. 

(iii) Now cross over the valencies of combining atoms. 

(iv) With first atom, we write the valency of second atom (as a subscript). 

(v) With second atom, we write the valency of first atom (subscript).

1. The valencies or charges on the ion must balance. 

2. When a compound consists of metal and non-metal, the name of the symbol of metal is written first, eg : Calcium oxide (CaO) 

3. In compounds formed with poly atomic ions, the ion is enclosed in a bracket before writing the number to indicate the ratio.

C) Both David and Dravid are correct.

Correct option is A) 2 –

Number of moles = n

Given mass = m

molar mass = M

Given number of particles = N

Avogodro number of particles = N₀

Atomic mass of carbon = 12u.

Atomic mass of one mole of carbon = 12g

But Atomic mas of carbon = 12 g mass of 6.022 × 10²³ carbon atoms = 12g.

= \(\frac{12}{6.022\times 10^{23}}\) gms

∴ Mass of carbon atoms

= 1.9926 x 10^-23 gm.

Correct option is

Correct option is C) chlorine

The working of hot air balloon can be explained with the help of Charles’ law. 

According to Charles’ law, at constant pressure, 

The volume of a fixed amount of a gas varies directly with the temperature. 

This means that as the temperature increases, 

The air inside the balloon expands and occupies more volume. 

Thus,

Hot air inside the balloon is less dense than the surrounding cold air. 

This causes the hot air balloon to float in air.

(b) (1) – b, (2) – d, (3) – a, (4) – c

Abraham Lincoln was elected President of the United States at age 52. Before he became President, he faced many setbacks. He failed in business, lost in legislative, senatorial and congressional races. He lost his sweetheart when he was 22. Thus, Lincoln had failed many times before he got the big success. He proved that defeat was a detour and not a dead end.

Socrates suggested that burning desire is the only secret to one’s success. I agree with this statement. If we don’t have a desire, we can’t achieve anything. A burning desire is the starting point of all accomplishments. A weak desire can’t produce great results. The motivation to get the success comes from the burning desire to achieve a purpose.

Correct option: (A) 24 g

4Al + 3O₂ → 2Al₂O₃

(108 g) (96 g) (204 g)

108 g Al combines with 96 g of O₂

27 g Al combines with \(\frac{96 \times 27}{108}\) =24 g

When Q > K_C the reaction will proceed in the reverse direction, 

i.e, formation of reactants.

When ice reaches its melting point, the energy supplied to the system (ice) is used to overcome the force of attraction between the solid particles and converts the solid into a liquid state. At this point, there is no rise in temperature. The energy is completely used in the change of state from solid to liquid (or also called melting). This heat energy used in the conversion is called the latent heat of fusion. It is called “latent” or hidden because the supplied heat energy is not used to raise the temperature of ice.

Median is that positional value of the variable which divides the distribution into two equal parts. One part comprises all values greater than or equal to median values and the other comprises all values less than or equal to it.

1. Median

2. Mode.

Arithmetic mean is a simple average of all items in a series it is simply mean value which is obtained by adding the values of all the items and dividing the total by the number of etc.

The weighted arithmetic mean will be greater than the simple arithmetic mean when items of small values are given less weights and items of big values are given more weights.

The direct method of computation of arithmetic mean can be used when the items in the serial are less.

Median is a centrally located value of series such that half of the values of the services are above it and other half below it.

1. It should be simple

2. It must be certain on character.

3. It should be capable of further mathematical or algebraic treatment.

1. First we find out the model class

2.  \(I_1+\frac{f_1-f_0}{zf_1 - f_0-f_2}\)

Z = Value of the mode

I₁ = Lower limit of the model classes

i = Size of the model group.

Mode is the value which occurs mode frequently in the series.

The sums of deviations of items about arithmetic mean is always equal to zero symbolically.

Mode is the most frequenctly observed date value it is denoted by M₀.

Correct answer is B.

Let the discarded number be x,

\(\frac{6(78)+x}{7}=81\)

(468 + x) = 567

x = 567 - 468

= 99

Correct answer is B.

1, 3, 3, 3, 5

Mean \(=\frac{(1+3+3+3+5)}{5}\)

\(=\frac{15}{5}\)

= 3

Median = 3^rd term

= 3

Mode = 3 (The highest occurring number)

For a given n, 

l = 0 to (n – 1) and for given l, 

m_l = -l…., 0…. + l

Therefore, 

The possible values of l and ml for n = 2 are :

A) Non-metallic character

Correct answer is: A. Metal 

Metallic bonds occur among metal atoms. Whereas ionic bonds join metals to non-metals, metallic bonding joins a bulk of metal atoms. A sheet of aluminum foil and a copper wire are both places where you can see metallic bonding in action

Answer is (C) 2

Answer is (A) 2s² 2p⁴

Correct Answer is: (b) (n-1) d (1-10) ns0^-1 or 2 

In general the electronic configuration of these elements is (n-1) d1–10 ns1–2. The (n–1) stands for the inner d orbital’s which may have one to ten electrons and the outermost ns orbital may have one or two electrons. The outer electronic configurations of the transition elements.

The Correct option is C. 2

Correct Answer is: (C) 4 

• There are four types of crystals: covalent, ionic, metallic, and molecular. Each type has a different type of connection, or bond, between its atoms.

• The type of atoms and the arrangement of bonds dictate what type of crystal is formed.

Correct Answer is: (A) Hydrogen bond 

In vapour state (~ 100 K). Sulphur partly exists as S₂ molecules like O₂ has two unpaired electrons in the anti-bonding π mole colour orbital and exhibits paramagnetism.

(A) Chlorine

Correct Answer is: (A) Transition element 

Represented in the periodic table as Zn, zinc is a transition metal, grouped with cadmium and mercury. 

The Correct option is A. PbO

B. Moist air

Correct Answer is: (B) He 

Answer is (A) Phenol

Answer is (A) Dumb-bell

Answer is (B) Na₂CO₃

Correct Answer is: C. Both A and B 

The ex-situ conservation strategies include botanical gardens, zoological gardens, conservation stands and gene, pollen, seed, seedling, tissue culture and DNA banks. Seed gene banks make the easiest way to store germplasm of wild and cultivated plants at low temperature.

The Correct option is A. Si