Atomic Structure

Chemistry, HSSC-Punjab First Year. This chapter is split into 40 topics and has 960 practice questions. The topics covered are listed below, followed by 10 free sample questions from the chapter.

Topics in this chapter

1. Allowed sets of quantum numbers 22 questions
2. Quantum numbers: overview 21 questions
3. Distribution of electrons in shells 30 questions
4. Quick Check 2.5 and 2.6 type items 21 questions
5. Hund's rule and orbital diagrams 23 questions
6. Behaviour of particles in an electric field 24 questions
7. Atomic number, proton number and nucleon number 25 questions
8. Valence electrons 25 questions
9. Atomic emission and absorption spectra 24 questions
10. Electronic configurations of elements 21 to 36 24 questions
11. Exercise based electronic structure items 22 questions
12. Magnetic quantum number 23 questions
13. Shapes of atomic orbitals 24 questions
14. Successive ionization energies and shells 24 questions
15. Azimuthal quantum number 24 questions
16. Properties of fundamental particles 24 questions
17. Ion configurations from atomic number and charge 26 questions
18. Fundamental particle calculations 20 questions
19. Spin quantum number 21 questions
20. Subshell designations from n and l 29 questions
21. Electronic configuration and the periodic table 23 questions
22. Semiconductors and electronic configuration 25 questions
23. Interpreting ionization energy data 24 questions
24. Free radicals 22 questions
25. Counting particles in atoms 25 questions
26. Noble gas core notation 28 questions
27. Counting subshells orbitals and electrons 29 questions
28. Ions of d-block elements 21 questions
29. Order of filling of subshells 23 questions
30. Ionization energy data from the exercises 20 questions
31. Pauli exclusion principle 21 questions
32. Unpaired electrons in atoms 26 questions
33. Deflection ratios and calculations 22 questions
34. Counting particles in ions 24 questions
35. Aufbau principle and the (n + l) rule 28 questions
36. Electronic configurations of elements 3 to 20 28 questions
37. Electronic configuration of ions 22 questions
38. Principal quantum number 21 questions
39. Quantum numbers of specific electrons 30 questions
40. The d and p orbitals 22 questions

Sample questions: Atomic Structure

10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.

Q1. Taking each mass as its mass number in amu, which of the ions H⁺, He²⁺, Li⁺, Na⁺ is deflected through the largest angle in the same electric field at the same speed?

• A. H⁺(correct answer)
• B. Na⁺
• C. Li⁺
• D. He²⁺

Answer: A.Angle is proportional to q/m: H⁺ = 1/1 = 1.000, He²⁺ = 2/4 = 0.500, Li⁺ = 1/7 = 0.143, Na⁺ = 1/23 = 0.043. The largest is H⁺.

Q2. Taking each mass as its mass number in amu, which of the ions He²⁺, Li⁺, Be²⁺, Mg²⁺ is deflected through the largest angle in the same electric field at the same speed?

• A. Mg²⁺
• B. Be²⁺
• C. He²⁺(correct answer)
• D. Li⁺

Answer: C.Angle is proportional to q/m: He²⁺ = 2/4 = 0.500, Li⁺ = 1/7 = 0.143, Be²⁺ = 2/9 = 0.222, Mg²⁺ = 2/24 = 0.083. The largest is He²⁺.

Q3. Taking each mass as its mass number in amu, which of the ions H⁺, Be²⁺, Al³⁺, Cl⁻ is deflected through the largest angle in the same electric field at the same speed?

• A. Be²⁺
• B. Al³⁺
• C. Cl⁻
• D. H⁺(correct answer)

Answer: D.Angle is proportional to q/m: H⁺ = 1/1 = 1.000, Be²⁺ = 2/9 = 0.222, Al³⁺ = 3/27 = 0.111, Cl⁻ = 1/35 = 0.029. The largest is H⁺.

Q4. Taking each mass as its mass number in amu, which of the ions Na⁺, Mg²⁺, Al³⁺, Ca²⁺ is deflected through the largest angle in the same electric field at the same speed?

• A. Ca²⁺
• B. Na⁺
• C. Mg²⁺
• D. Al³⁺(correct answer)

Answer: D.Angle is proportional to q/m: Na⁺ = 1/23 = 0.043, Mg²⁺ = 2/24 = 0.083, Al³⁺ = 3/27 = 0.111, Ca²⁺ = 2/40 = 0.050. The largest is Al³⁺.

Q5. Taking each mass as its mass number in amu, which of the ions Na⁺, Mg²⁺, Al³⁺, Ca²⁺ has the largest radius of deflection in the same field at the same speed?

• A. Al³⁺
• B. Na⁺(correct answer)
• C. Ca²⁺
• D. Mg²⁺

Answer: B.The radius is proportional to m/q: Na⁺ = 23.00, Mg²⁺ = 12.00, Al³⁺ = 9.00, Ca²⁺ = 20.00. The largest radius belongs to Na⁺.

Q6. Taking each mass as its mass number in amu, which of the ions H⁺, Li⁺, Na⁺, K⁺ is deflected through the largest angle in the same electric field at the same speed?

• A. Li⁺
• B. H⁺(correct answer)
• C. K⁺
• D. Na⁺

Answer: B.Angle is proportional to q/m: H⁺ = 1/1 = 1.000, Li⁺ = 1/7 = 0.143, Na⁺ = 1/23 = 0.043, K⁺ = 1/39 = 0.026. The largest is H⁺.

Q7. Taking each mass as its mass number in amu, which of the ions He²⁺, Na⁺, Al³⁺, Cl⁻ is deflected through the largest angle in the same electric field at the same speed?

• A. Cl⁻
• B. Na⁺
• C. He²⁺(correct answer)
• D. Al³⁺

Answer: C.Angle is proportional to q/m: He²⁺ = 2/4 = 0.500, Na⁺ = 1/23 = 0.043, Al³⁺ = 3/27 = 0.111, Cl⁻ = 1/35 = 0.029. The largest is He²⁺.

Q8. Taking each mass as its mass number in amu, which of the ions Li⁺, Mg²⁺, Ca²⁺, K⁺ is deflected through the largest angle in the same electric field at the same speed?

• A. K⁺
• B. Li⁺(correct answer)
• C. Ca²⁺
• D. Mg²⁺

Answer: B.Angle is proportional to q/m: Li⁺ = 1/7 = 0.143, Mg²⁺ = 2/24 = 0.083, Ca²⁺ = 2/40 = 0.050, K⁺ = 1/39 = 0.026. The largest is Li⁺.

Q9. Taking each mass as its mass number in amu, which of the ions Be²⁺, Mg²⁺, Ca²⁺, Cl⁻ is deflected through the largest angle in the same electric field at the same speed?

• A. Mg²⁺
• B. Be²⁺(correct answer)
• C. Ca²⁺
• D. Cl⁻

Answer: B.Angle is proportional to q/m: Be²⁺ = 2/9 = 0.222, Mg²⁺ = 2/24 = 0.083, Ca²⁺ = 2/40 = 0.050, Cl⁻ = 1/35 = 0.029. The largest is Be²⁺.

Q10. How many of the valence-shell electrons of mercury (6s²) have spin 'up', i.e. an upward arrow (Exercise Q.2 f iv)?

• A. 1(correct answer)
• B. 2
• C. 0
• D. 10

Answer: A.The 6s orbital holds one up and one down arrow (the book's label for the sign of s is inconsistent, but one electron has each direction).