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Indian Navy SSR Atomic combinations — practice questions

Explore 33 free Atomic combinations questions in Indian Navy SSR Chemistry. Open each question or exercise to read its content, reference answers and available explanation.

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Atomic combinations questions and exercises with answers

Showing questions 1–30 of 33.

For Bohr's hydrogen-like atom, what is the velocity of electron in n-th orbit (in terms of fine structure constant α and c)?Read the answer and worked solution →In vacuum, the velocity of electromagnetic radiation isRead the answer and worked solution →The wave number of a photon of frequency $6 \times 10^{14}\,Hz$ (in vacuum) isRead the answer and worked solution →In the photoelectric effect, the *stopping potential* $V_0$ varies with the frequency of incident light asRead the answer and worked solution →The Bohr orbit velocity of the ground-state electron in hydrogen is aboutRead the answer and worked solution →As per your syllabus, what is the MOLECULAR MASS of methane (CH₄) — using C = 12.011 u and H = 1.008 u?Read the answer and worked solution →As per your syllabus, what is the energy of the first orbit of He⁺ (Z = 2, n = 1)?Read the answer and worked solution →Order the atomic models as they were proposedRead the answer and worked solution →Match each scientist to their modelRead the answer and worked solution →Match each model to what it could NOT explainRead the answer and worked solution →True or false: Rutherford's modelRead the answer and worked solution →True or false: Bohr's modelRead the answer and worked solution →Complete the reason Bohr's model failsRead the answer and worked solution →Which model does this belong to?Read the answer and worked solution →Match each quantum number to what it is calledRead the answer and worked solution →True or false: the quantum mechanical modelRead the answer and worked solution →Order the structure: from atom down to electronRead the answer and worked solution →Complete the (n + l) ruleRead the answer and worked solution →True or false: orbital energiesRead the answer and worked solution →Match each rule to what it forbids or requiresRead the answer and worked solution →Tap every statement Hund's rule requiresRead the answer and worked solution →The fundamental particlesRead the answer and worked solution →Assertion and reasonRead the answer and worked solution →Two are true, one is notRead the answer and worked solution →Three of these are wrong. Find the one that holds.Read the answer and worked solution →Which principle is being described?Read the answer and worked solution →Flip and pair: symbol with meaningRead the answer and worked solution →Spot the one that does not belongRead the answer and worked solution →Tap every statement true of the Schrodinger modelRead the answer and worked solution →Reading the models backRead the answer and worked solution →

Worked practice questions

For Bohr's hydrogen-like atom, what is the velocity of electron in n-th orbit (in terms of fine structure constant α and c)?

  1. v_n = c / Z
  2. v_n = c α Z / n (where α ≈ 1/137)
  3. v_n = c
  4. v_n = c × n
Show answer and solution

Correct answer: B. v_n = c α Z / n (where α ≈ 1/137)

v_n = (1/n) × (Zα c) where α = e²/(4πε₀ ħc) ≈ 1/137 is the fine structure constant. **For H ground state:** v₁ ≈ c/137 ≈ 2.19 × 10⁶ m/s. Relativistic effects small for light atoms, but become significant for heavy atoms (high Z).

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In vacuum, the velocity of electromagnetic radiation is

  1. $3 \times 10^{8}\,m\,s^{-1}$
  2. $3 \times 10^{5}\,m\,s^{-1}$
  3. $3 \times 10^{6}\,m\,s^{-1}$
  4. $3 \times 10^{10}\,m\,s^{-1}$
Show answer and solution

Correct answer: A. $3 \times 10^{8}\,m\,s^{-1}$

All EM radiation travels at $c = 3 \times 10^{8}\,m\,s^{-1}$ in vacuum, regardless of wavelength.

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The wave number of a photon of frequency $6 \times 10^{14}\,Hz$ (in vacuum) is

  1. $5 \times 10^{-7}\,m^{-1}$
  2. $2 \times 10^{6}\,m^{-1}$
  3. $2 \times 10^{4}\,m^{-1}$
  4. $1.8 \times 10^{23}\,m^{-1}$
Show answer and solution

Correct answer: B. $2 \times 10^{6}\,m^{-1}$

$\bar{\nu} = \nu/c = (6 \times 10^{14})/(3 \times 10^{8}) = 2 \times 10^{6}\,m^{-1}$.

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