Chemistry Test

Result

Chemistry Test - 2

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

What is the atomic number of Nitrogen?

A
7

B
8

C
9

D
10

Solution

Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772.
Question 2
1 / -0

Which of the following is not a fossil fuel?

A
Oil

B
Natural gas

C
Geothermal

D
Coal.

Solution

There are many advantages to using geothermal energy either directly or indirectly: Geothermal energy is renewable; it is not a fossil fuel that will be eventually used up. The Earth is continuously radiating heat out from its core, and will continue to do so for billions of years.
Question 3
1 / -0

Rn decay into Po by emitting a -particles with half-life of 4 days. A sample contains 6.4 × 10¹⁰atom of Rn. After 12 days, the number of atoms of Rn left in the sample will be?

A
0.8 × 10¹⁰

B
2.1 × 10¹⁰

C
3.2 × 10¹⁰

D
0.3 × 10¹⁰

Solution

Given:
The half life of Radon, $t 1 / 2=4$ days
No of atoms, $N=6.4 \times 10^{10}$
Total time, $T=12$ days
To Find: --The no of atoms of Radon left in the sample after 12 days.
Calculation:
- The no of half lives in total time, $n=12 / 4=3$
- No of atoms left after 3 half lives $=\mathrm{N} \times\left(1 / 2^{\mathrm{n}}\right)$
$\Rightarrow$ No of atoms left $=6.4 \times 10^{10} \times\left(1 / 2^{3}\right)$
$\Rightarrow$ No of atoms left $=0.8 \times 10^{10}$
- So, the correct answer is
(a) $0.8 \times 10^{10}$
Question 4
1 / -0

What is the number of periods in the modern periodic table?

A
2

B
6

C
7

D
8

Solution

There are currently seven complete periods in the periodic table, comprising the 118 known elements.
Question 5
1 / -0

Which of the following is/are a stage in the Nitrogen Cycle?

A
Assimilation.

B
Ammonification

C
Denitrification

D
All of the above

Solution

The nitrogen cycle helps to explain as to how nitrogen flows between animals, bacteria, plants, the atmosphere, and the soil on earth.

Processes of the Nitrogen Cycle

Nitrogen fixation is the process of converting the atmospheric nitrogen (N2) into biological state nitrogen.

Nitrification is the process where the ammonium ions (NH4) are converted into nitrides, first into nitrites (NO2 - ) then into nitrate (NO3 - ) which is done by the nitrogen-fixing bacteria.

Assimilation refers to how plants and animals obtain nitrogen. Plant roots absorb nitrates from the soil into the roots then into the entire plant system.

Ammonification is also termed as the decaying process. It occurs when the plant or animal dies then decomposers such as fungi and bacteria decompose the tissues and transforms the nitrogen back into ammonium.

Denitrification is the process that changes nitrate to nitrogen gas, hence returning it into the atmosphere. This process releases the excess nitrogen in the soil back into the atmosphere
Question 6
1 / -0

If λ₀ is the de-Broglie wavelength for a proton accelerated through a potential difference of 100 V, the de-Broglie wavelength for alpha-particle accelerated through the same potential difference is?

A
$2 \sqrt{2} λ_{0}$

B
$\frac{λ_{0}}{2}$

C
$\frac{λ_{0}}{2 \sqrt{2}}$

D
$\frac{λ_{0}}{\sqrt{2}}$

Solution

As de-Broglie wavelength is given by $\lambda=\frac{h}{m v}=\frac{h}{\sqrt{2 m(K . E)}}$ $\lambda=\frac{h}{\sqrt{2 m q V}}$ where $v=\operatorname{accelerating}$ potential
$q=$ charge
$\lambda_{p}=\frac{h}{\sqrt{2 m_{p} q_{p} v}}$
$\alpha=^{4} H e^{+}$
$\Rightarrow r q_{a}=2 q_{p}$
$m_{\alpha}=4 m_{p}$
$\lambda_{\alpha}$ at same accelerating potential
$\lambda_{\mathrm{a}}=\frac{h}{\sqrt{2 \times 4 m_{p} \times 2 q_{p} \times v}}$
$\lambda_{\alpha}=\frac{h}{\sqrt{2 m_{p} q_{p} v} \times \sqrt{8}}=\frac{\lambda p}{2 \sqrt{2}}$
Given $\lambda_{p}=\lambda$
$\Rightarrow \lambda_{\alpha}=\frac{\lambda}{2 \sqrt{2}}$
Question 7
1 / -0

Of which element is diamond a solid form?

A
Carbon

B
Nitrogen

C
Oxygen

D
Hydrogen

Solution

Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic.
Question 8
1 / -0

pH value of X is 14. X is_____.

A
weak acid

B
strong acid

C
weak base

D
strong base

Solution

Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, it represents an increase in OH” ion concentration in the solution, that is, increase in the strength of base.
Question 9
1 / -0

Which of the following are generally used as fuel for Nuclear reactors?

A
Potassium

B
Argon

C
Uranium

D
None of the above.

Solution

Uranium is a naturally-occurring element in the Earth's crust. Traces of it occur almost everywhere, although mining takes place in locations where it is naturally concentrated.

The uranium ore requires to make fuel for nuclear. Uranium is to be extracted from the rock in which it is found, then enriched in the uranium-235 isotope, before being made into pellets that are loaded into assemblies of nuclear fuel rods.
Question 10
1 / -0

The bond order of N₂ is?

A
3

B
2

C
1

D
0

Solution

Bond order is the number of chemical bonds between a pair of atoms and indicates the stability of a bond. The bond order of N₂ is 3.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Chemistry Test - 2

Result

Chemistry Test - 2

Score

-

Rank

-

SHARING IS CARING

Question 1

7

8

9

10

Solution

Question 2

Oil

Natural gas

Geothermal

Coal.

Solution

Question 3

0.8 × 1010

2.1 × 1010

3.2 × 1010

0.3 × 1010

Solution

Question 4

2

6

7

8

Solution

Question 5

Assimilation.

Ammonification

Denitrification

All of the above

Solution

Question 6

22λ0

λ02

λ022

λ02

Solution

Question 7

Carbon

Nitrogen

Oxygen

Hydrogen

Solution

Question 8

weak acid

strong acid

weak base

strong base

Solution

Question 9

Potassium

Argon

Uranium

None of the above.

Solution

Question 10

3

2

1

0

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.

0.8 × 10¹⁰

2.1 × 10¹⁰

3.2 × 10¹⁰

0.3 × 10¹⁰

$2 \sqrt{2} λ_{0}$

$\frac{λ_{0}}{2}$

$\frac{λ_{0}}{2 \sqrt{2}}$

$\frac{λ_{0}}{\sqrt{2}}$