General Science Jkssb Chemistry Set 1 Mcqs (504 MCQs) | JKSSB & SSC Quiz

General Science

jkssb chemistry set 1 mcqs

Download PDF

Topics

jkssb physics set 1 mcqs jkssb chemistry set 1 mcqs jkssb biology set 1 mcqs

Practice Questions

504 Total
Question 171 Discuss
Ask a Friend

The unit of density is:

A
metre cubed
B
metre squared
C
kilogram metre per second
D
kilogram per cubic metre

Answer & Explanation

Correct Option: D

In the formal International System of Units (SI), density is defined mathematically as an object's mass divided by its volume (ρ = m/V). Consequently, the universally accepted derived SI unit for density is kilograms per cubic meter (kg/m3).
Question 172 Discuss
Ask a Friend

Who arranged the 56 elements in an ascending order of their atomic mass and found that each 8th element had the same properties?

A
Van Spronsen
B
John Newlands
C
Dmitri Mendeleev
D
Lothar Meyer

Answer & Explanation

Correct Option: B

In 1864, the English chemist John Newlands published an early version of the periodic table based on his 'Law of Octaves.' He historically compared this periodic repetition of chemical properties to the octaves found in a musical scale, though his peers initially ridiculed the idea.
Question 173 Discuss
Ask a Friend

Identify an element that does NOT belong to period 4.

A
Zinc
B
Potassium
C
Calcium
D
Lithium

Answer & Explanation

Correct Option: D

Period 4 of the periodic table includes prominent elements ranging from Potassium (K) through Krypton (Kr), characterized by the active filling of the fourth principal energy shell. Lithium (Li) does not belong because it is a much lighter alkali metal firmly located in Period 2.
Question 174 Discuss
Ask a Friend

Who introduced the term 'triads' in the classification of elements?

A
Dmitri Mendeleev
B
Johann Dobereiner
C
AEB de Chancourtois
D
John Newlands

Answer & Explanation

Correct Option: B

During the 1820s, German chemist Johann Wolfgang Döbereiner historically identified several groups of three chemically similar elements, which he called 'triads' (e.g., chlorine, bromine, iodine). This early pattern recognition was a vital stepping stone toward the eventual development of the modern periodic table.
Question 175 Discuss
Ask a Friend

Which of the following processes occurs during decomposition in soil?

A
Defragmentation
B
Humification
C
Oxidation
D
Crystallisation

Answer & Explanation

Correct Option: B

Humification is a vital biochemical process occurring during soil decomposition where dead organic matter breaks down completely into humus. This dark, nutrient-rich organic material is highly resistant to further decay and dramatically improves overall soil structure and fertility.
Question 176 Discuss
Ask a Friend

Who used the drawing circle and arrow symbols to represent the atoms of different elements in 1803?

A
Amedeo Avogadro
B
Antoine Lavoisier
C
Jacob Berzelius
D
John Dalton

Answer & Explanation

Correct Option: D

In 1803, pioneer chemist John Dalton was the very first to visually represent distinct elemental atoms using unique, specific circular symbols. This historical, visual codification system laid the crucial groundwork for modern chemical formulas, even though Berzelius's letter-based system eventually replaced it.
Question 177 Discuss
Ask a Friend

Which element is the first element in group 13 of the periodic table?

A
Boron
B
Gallium
C
Indium
D
Aluminium

Answer & Explanation

Correct Option: A

Boron, holding an atomic number of 5, sits at the very top of Group 13, historically known as the boron group or earth metals. Unlike the fully metallic elements located directly beneath it (like aluminum), boron is classified as a brittle, black metalloid.
Question 178 Discuss
Ask a Friend

Identify the atomic number of an element that belongs to group 17.

A
10
B
11
C
17
D
18

Answer & Explanation

Correct Option: C

Chlorine is a Group 17 halogen with an atomic number of 17, whereas 10 is Neon, 11 is Sodium, and 18 is Argon.
Question 179 Discuss
Ask a Friend

Identify the correct statement related to metallic character.

A
Metallic character decreases across a group and stays the same down a group.
B
Metallic character decreases across a period and increases down a group.
C
Metallic character increases across a period and decreases down a group.
D
Metallic character stays the same across a period and decreases the same down a group.

Answer & Explanation

Correct Option: B

As you move across a period, atoms hold their electrons more tightly, decreasing metallic character; moving down a group, outer electrons are further from the nucleus, making them easier to lose and increasing metallic character.
Question 180 Discuss
Ask a Friend

Who among the following coined the name oxygen for the element released by mercury oxide in 1779?

A
Martin Klaproth
B
John Dalton
C
Jons Jacob Berzelius
D
Antoine Lavoisier

Answer & Explanation

Correct Option: D

Antoine Lavoisier recognized and named oxygen in 1779, debunking the prominent phlogiston theory and correctly establishing the element's crucial role in combustion.
Previous Next