1. The diameter of an atom is in the order of
A. 0.2m
B. 0.2mm
C. 0.2nm
D. 0.2pm
✅ The correct answer is option C.
Basic Concept MCQs
2. Which of the following are isoelectronic species?
A. H+ HH-
B. Li+ Na+ K+
C. C1- Br- I
D. F- Ne Na+
✅ The correct answer is option D.
3. The mass spectrometer is used to determine the Mass number of isotopes and
A. Atomic number
B. Relative abundance
C. Electronic configuration
D. All of the above
✅ The correct answer is option B.
4. Molecular ions are formed by passing
A. High energy electron beam
B. – particle
C. X-rays
D. All of the above
✅ The correct answer is option D.
5. The number of peaks obtained in mass spectrometry shows
A. Relative abundance
B. The average mass of the element
C. Number of isotopes
D. Relative isotopic mass
✅ The correct answer is option C.
6. The empirical formula of chloroform is
A. CH2 C12
B. CH3C1
C. CC14
D. CHC13
✅ The correct answer is option D.
7. 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.
8. 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.
9. 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.
10. 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.