α-particle consists of
Held on 30 Apr 2019 · Verified 9 Jul 2026.
2 protons and 2 neutrons only
2 electrons, 2 protons and 2 neutrons
2 electrons and 4 protons only
2 protons only
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De-Broglie wavelength of an electron orbiting in the $n=2$ state of hydrogen atom is close to (Given Bohr radius $=0.052 \mathrm{~nm}$ )
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