The neutron was discovered by James Chadwick in 1932 by bombarding which element with alpha particles?
A. Lead
B. Gold
C. Beryllium
D. Uranium
Answer: Option C
Solution (By JKExamLibrary)
Chadwick bombarded beryllium (Be) with alpha particles from polonium, producing a highly penetrating neutral radiation, which he identified as neutrons: ⁹Be + ⁴He → ¹²C + ¹n. Gold was used by Rutherford for nucleus discovery. Uranium for fission. Lead for shielding.
Explanation:
HCl + NaOH → NaCl + H₂O. This is a neutralization reaction producing sodium chloride (common salt). NaNO₃ from HNO₃, Na₂SO₄ from H₂SO₄, Na₂CO₃ from H₂CO₃ (weak acid).
Explanation:
John Dalton proposed the atomic theory in 1803. His theory stated that all matter is made of indivisible and indestructible atoms, atoms of a given element are identical in mass and properties, and compounds are formed by combinations of different atoms in fixed ratios.
Explanation:
Urea, CO(NH₂)₂, is a straight nitrogenous fertilizer with about 46% N. It contains no phosphorus or potassium. It is converted to ammonium carbonate in soil by urease enzyme, then to nitrates.
No comments yet. Be the first to start the discussion!