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

Some Important Elements MCQs with Answers

Includes 16 past paper MCQs (marked).

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Some Important Elements MCQs (141–145)

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

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141.
Inner transition elements are called?
Correct Answer: D. All of these
One-liner
Inner transition elements are called All of these (lanthanides, actinides, and rare earth elements).
142.
An atom of Iron is times as heavy as atom of hydrogen.
Correct Answer: A. 55
One-liner
An atom of Iron is 55 times as heavy as an atom of hydrogen.
143.
Relative atomic mass of Na is ?
Correct Answer: D. 22.989769 g
One-liner
The relative atomic mass of sodium (Na) is 22.989769 g.
144.
Which of the following is used in semiconductors?
Correct Answer: C. Silicon
One-liner
Silicon is the primary element used in semiconductors for manufacturing electronic components like transistors and microchips.
145.
Which of the following elements has the same oxidation number in all its compounds?
Correct Answer: D. Fluorine
One-liner
Fluorine is the only element that always exhibits an oxidation number of –1 in all its compounds.