Practice GAT Subject Chemistry questions with answers and explanations.
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Rutherford concluded that atoms contain a small dense positive nucleus.
Most atomic volume is empty space.
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Thomson's cathode-ray experiments revealed negatively charged particles.
He proposed an early model with electrons in positive matter.
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Chadwick identified the neutral nuclear particle in 1932.
Neutrons explain isotopic mass differences.
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Quantum mechanics describes electron probability distributions.
An orbital can hold up to two electrons with opposite spins.
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The Pauli exclusion principle allows two electrons per orbital.
They must have opposite spin quantum numbers.
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Oxygen contributes 16 of the 18 g/mol formula mass.
16/18×100 ≈ 88.9%.
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The coefficients of H2 and H2O are equal.
Thus 4 mol H2 produce 4 mol H2O.
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The mole ratio H2:NH3 is 3:2.
6 mol H2×2/3 = 4 mol NH3.
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Percent yield is actual divided by theoretical times 100.
8/10×100 = 80%.
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Molarity equals moles divided by liters of solution.
0.50/2.0 = 0.25 M.
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Atomic number identifies the element.
In a neutral atom it also equals the number of electrons.
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Particles equal moles times Avogadro's number.
0.5×6.022×10^23 = 3.011×10^23 molecules.
