Same chapter3 marksDifficulty: Medium
An element has two isotopes of mass numbers 35 and 37 present in the ratio 3 : 1. Calculate its average atomic mass.
Atomic Structure and Chemical Bonding
3 marksDifficulty: Medium
Explain the formation of a molecule of methane, naming the type of bond.
Original Khojo Papers practice question — not from a past board paper.
Answer
A carbon atom has four electrons in its outermost shell and needs four more for an octet. Each of four hydrogen atoms shares its single electron with carbon, and carbon shares one electron with each. Four shared pairs are formed, so carbon attains eight electrons and each hydrogen two. The bonds are covalent.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The molecule is tetrahedral, though this is not required at this level.
Related questions
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Same chapter3 marksDifficulty: Medium
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Same chapter3 marksDifficulty: Medium
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Same chapter3 marksDifficulty: Medium
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Atomic Structure and Chemical Bonding