111) Which of the following atomic numbers of elements have similar chemical properties
A) 7, 8, 9
B) 9, 17, 35
C) 3, 10, 11
D) 10, 11, 12
View Answer
B) 9, 17, 35
Explanation:Elements with similar chemical properties belong to the same group.9 (F) , 17 (Cl), 35 (Br)→ Halogens(Group 17)
Answer: 9, 17, 35
112) In the modern periodic table group 2 (IIA) elements are called as
A) Alkali metals
B) Alkaline earth metals
C) Halogens
D) Noble gases
View Answer
B) Alkaline earth metals
Explanation:Group 2 (IIA) elements like Be, Mg, Caare called alkaline earth metals.
Answer: Alkaline earth metals
113) The valency of calcium is
A) 1
B) 2
C) 3
D) 4
View Answer
B) 2
Explanation:Calcium (Ca) has atomic number 20 and electronic configuration: 2, 8, 8, 2 → valency = 2
Answer: 2
114) Atomic number of an element is 17. then the period to which this element belongs
A) 1
B) 2
C) 3
D) 4
View Answer
C) 3
Explanation:Element with atomic number 17 is Cl, and it is in 3rd period.
Answer: 3
115) Which one of the following is strong acid
A) CH3COOH
B) HCl
C) H2O
D) NH4OH
View Answer
B) HCl
Explanation:HClis a strong acid, while CH₃COOH is weak, NH₄OH is weak base.
Answer: HCl
