Who discovered the electron and determined its charge-to-mass ratio?
A. Ernest Rutherford
B. James Chadwick
C. J. J. Thomson
D. Niels Bohr
Answer: Option C
Solution (By JKSSB Mock Tests)
J.J. Thomson discovered the electron through cathode ray tube experiments in 1897 and measured the e/m ratio by applying electric and magnetic fields. Rutherford discovered the nucleus via the gold foil experiment. Chadwick discovered the neutron (1932). Bohr proposed the planetary model of the atom with quantized orbits. Thomson's model (plum pudding) was later superseded. Exam memory: Thomson = electron (e/m); Rutherford = nucleus; Chadwick = neutron; Bohr = energy levels.
Explanation:
CO has a triple bond: one sigma and two pi bonds, with a coordinate covalent character where oxygen donates a lone pair to carbon, forming a bond similar to triple bond. Total shared electrons = 6 (three pairs). Lewis structure shows :C≡O: with formal charges. The bond order is 3. It is isoelectronic with N₂ and CN⁻.
Explanation:
Sodium displaces hydrogen from water, a single displacement reaction. It is also a redox reaction (Na oxidized, H⁺ reduced). Not combination (one product), not decomposition (one reactant), not double displacement.
Explanation:
Detergents emulsify grease by forming micelles around oil droplets, removing them from fabric. Soap does same but less effective in hard water.
No comments yet. Be the first to start the discussion!