261. Which one is true about isotope?
A. Same number of neutrons
B. Same mass number
C. Same physical properties
D. Same chemical properties
✅ The correct answer is option D.
Chemistry
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262. Which set of elements is listed in order of increasing ionization energy?
A. Sb < As < S < P < Cl
B. Cl < Sb < P < As < S
C. As < Cl < P < S < Sb
D. Sb < As < Cl < S < P
✅ The correct answer is option A.
263. Which of the following compounds will react with Tollens reagent?
A. CH3-CHO
B. CH3-CH-CH3
C. CH3-COOH
D. CH3-CO-CH2-CH3
✅ The correct answer is option A.
264. The molecular mass of water (18g) means
A. 1-mole molecules of water
B. 1-gram molecule of water
C. 3-gram atoms
D. all
✅ The correct answer is option D.
265. Which of the following always increases on going from top to bottom in a group?
A. Metallic character
B. Electronegativity
C. Oxidizing power
D. The tendency to get reduced
✅ The correct answer is option A.
266. Which of the following reactions may be associated with aldehyde and ketone?
A. Nucleophile addition
B. Polymerization
C. Oxidation
D. All of the above
✅ The correct answer is option D.
267. Which of the following ion formation is always exothermic?
A. Uni-negative
B. Uni-positive
C. Di-negative
D. Di-positive
✅ The correct answer is option A.
268. Which of the p-block elements are not representative elements?
A. Alkali metals (I-A)
B. Group-14 elements (IV-A)
C. Group-18 elements (VII-A)
D. Halogens (VII-A)
✅ The correct answer is option C.
269. Which of the following statements about isotopes is correct?
A. Isotopes with the odd atomic number are abundant
B. Isotopes with the odd atomic number and even mass number are abundant
C. Isotopes with an even atomic number and even mass number are abundant
D. Isotopes with an even atomic number and odd mass no are abundant
✅ The correct answer is option C.
270. Among halogens, the highest boiling point is of
A. Florine
B. Chlorine
C. Bromine
D. Iodine
✅ The correct answer is option D.