Atomic number of an element is 17. It belongs to which group and period?
A. Group 1, Period 3
B. Group 18, Period 3
C. Group 17, Period 3
D. Group 16, Period 2
Answer: Option C
Solution (By JKSSB Mock Tests)
Atomic number 17 is chlorine. Electronic configuration: 2,8,7. Period number = number of shells = 3. Group number = 10 + valence electrons (for p-block elements) = 10+7 = 17. Hence Group 17 (halogens), Period 3. Group 1 has 1 valence electron, Group 16 has 6, Group 18 has 8 (except He). Simple method: period = number of shells.
Explanation:
Nickel (finely divided) catalyzes the addition of hydrogen to unsaturated vegetable oils to form solid vanaspati ghee. It provides surface for reaction. Platinum and palladium also work but are expensive. Iron is used in Haber process. V₂O₅ in Contact process.
Explanation:
Detergents do not form scum with Ca²⁺/Mg²⁺, so they clean effectively in hard water. Soaps form insoluble precipitates. Biodegradability varies; some detergents are non-biodegradable.
Explanation:
Finely divided nickel catalyzes the addition of hydrogen to liquid oils to form solid fats (vanaspati ghee). Platinum/palladium also work but are expensive. Iron is used in Haber process; V₂O₅ in Contact process.
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