Which element is in a liquid state at normal room temperature?

C. Gallium (near room temperature)

Valency of hydrogen and Potassium is _

B. +1 for hydrogen and +2 for potassium

C. +2 for hydrogen and +1 for potassium

Everyday Science · Atoms, Elements & Compounds · page 8 of 15

Some Important Elements MCQs with Answers

Includes 16 past paper MCQs (marked).

Timed quizzes, instant results, track your progress — free

Practice these MCQs in the app

All Everyday Science chapters

Some Important Elements MCQs (71–80)

10 MCQs with answers and a short one-liner. Hide answers to test yourself.

Past paper MCQs in this chapter · See all past papers

Answers and one-liners are hidden. Tap an option to check that question, or show all.

71.
Which of the following elements shows the maximum oxidation state?
Correct Answer: A. Mn
One-liner
Manganese (Mn) shows the maximum oxidation state of +7 among the given elements.
72.
Which element is in a liquid state at normal room temperature?
Correct Answer: D. All of these
One-liner
All of these — Bromine and Mercury are liquid at normal room temperature, while Gallium melts slightly above room temperature (around 29.8°C) and can liquefy in one's hand.
73.
Valency of hydrogen and Potassium is _
Correct Answer: A. +1 for both
One-liner
The valency of both hydrogen and potassium is +1.
74.
Which gives blue color in borax bead test?
Correct Answer: A. Cobalt
One-liner
In the borax bead test, cobalt gives a deep blue color in both oxidizing and reducing flames.
75.
Carbon is a _?
Correct Answer: C. Tetravalent
One-liner
Carbon is tetravalent, meaning it has four valence electrons and can form four covalent bonds.
76.
Which is the third most abundant element in the Earth's crust?
Correct Answer: B. Aluminum
One-liner
The third most abundant element in the Earth's crust is Aluminum (after oxygen and silicon).
77.
What is the atomic number of chlorine?
Correct Answer: C. 17
One-liner
The atomic number of chlorine is 17.
78.
Atomic number of iron is?
Correct Answer: B. 26
One-liner
The atomic number of iron is 26.
79.
Number of elements present in fifth period of periodic table is _?
Correct Answer: B. 18
One-liner
The fifth period of the periodic table contains 18 elements.
80.
Past Paper MCQ
The element used in glass preparation due to the transparent nature of its compounds is _?
Correct Answer: D. Silicon
One-liner
The element used in glass preparation due to the transparent nature of its compounds is Silicon.

Previous chapter: Non-metal Elements Next chapter: Compounds

Some Important Elements MCQs with Answers

Some Important Elements MCQs (71–80)

Subjects

Exams

Platform

Legal