5 public questions tagged with this topic.
Ni²⁺ + 2e⁻ → Ni . 1 mol Ni (54 g) requires 2F. Moles = (0.54/54) = 0.01 mol , Charge = 0.01 × 2 × 96500 = 1930 C .
Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Electrochemical Cells - Galvanic Cells and Electrode Potential
Moles of gas ≈ 0.067 mol; total mass = 1 g. Molar mass ≈ 14.93 g/mol. Moles: C ≈ 0.0625, H = 0.25; per molecule: C ≈ 1, H ≈ 4. Molecular formula = CH₄.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
Reaction: C + O₂ → CO₂. Moles: C ≈ 0.8333 mol, O₂ = 0.75 mol. O₂ limits; 0.75 mol CO₂ formed = 0.75 × 44 = 33 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Mass number reflects total nucleons conserved unless alpha particle is ejected. In beta-minus decay, a neutron inside nucleus transforms into proton, electron, and antineutrino. Proton number rises by one, shifting element up one group, but total count of protons plus neutrons remains identical because neutron loss balances proton gain. Hence atomic mass unchanged. Alpha decay reduces mass by four, positron emission also preserves mass but decreases atomic number. Gamma decay emits only energy with no nucleon change. Therefore beta-minus decay exemplifies conservation of mass number during atomic number change.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
14C and 14N accurately defines or describes the concept asked in this question. Within Atoms and Molecules, precise definitions and terminology are essential for clear scientific communication. The other options (1H and 3H, 3H and 4He, and 140Ba and 140Th) either describe related but distinct concepts, use incorrect terminology, or confuse similar-sounding terms that have different scientific meanings. A thorough understanding of exact definitions helps distinguish between closely related biological concepts and is crucial for competitive examinations.
Ref: Campbell Biology, Urry et al., 12th Ed.
