जॉन डाल्टन ने किस वर्ष अपना परमाणु सिद्धांत प्रस्तुत किया था, जिसका दूसरा भाग यह बताता है कि किसी विशेष तत्व के सभी परमाणु समान होते हैं?

Which postulate of Dalton's Atomic Theory was proven incorrect by the discovery of subatomic particles?

What is the correct chemical symbol for a species containing 20 protons, 18 electrons, and 22 neutrons?

Which of the following sets of quantum numbers are permissible? (J) n = 3, ℓ = 3, m = 2, s = +12 (K) n = 2, ℓ = 2, m = 1, s = -12 (L) n = 1, ℓ = 0, m = 0, s = -12 (M) n = 3, ℓ = 2, m = 1, s = -12 Choose the correct option: