Science
The electronic configuration of three elements X, Y and Z are X - 2, 8, 7; Y - 2, 8, 2; and Z - 2, 8
options
- Y and Z are metals
- Y and X are non-metals
- X is a non-metal and Y is a metal
- Y is a non-metal and Z is a metal
Answer
X is a non-metal and Y is a metal
Reason —
- X : 2, 8, 7 → 7 valence electrons (like chlorine) so it tends to gain 1 electron to complete the octet, a typical non-metal behaviour.
- Y : 2, 8, 2 → 2 valence electrons (like magnesium) so it readily loses 2 electrons to form Y2+, which is characteristic of metals.
- Z : 2, 8 → complete octet (neon) so it is an inert noble gas.
Thus, X is a non-metal and Y is a metal.
Related Questions
An aqueous solution ‘A’ turns the phenolphthalein solution pink. On addition of an aqueous solution ‘B’ to ‘A’, the pink colour disappears. Which of the following statement is true for the solutions ‘A’ and ‘B’.
options
- A is strongly basic and B is a weak base.
- A is strongly acidic and B is a weak acid.
- A has a pH greater than 7 and B has a pH less than 7.
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options
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options
- Burning of candle.
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options
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