1(xv)
A nucleus of an atom consists of 146 neutrons and 95 protons. It decays after emitting an alpha particle. How many protons and neutrons are left in the nucleus after an alpha emission?
- (a)protons = 93, neutrons = 142
- (b)protons = 95, neutrons = 144
- (c)protons = 93, neutrons = 144
- (d)protons = 95, neutrons = 142
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protons = 93, neutrons = 144
Reason — An alpha particle consists of two protons and two neutrons. Emission of alpha particle reduces the number of protons by 2 and also the number of neutrons by 2. Hence, number of protons = 95 - 2 = 93 and number of neutrons = 146 - 2 = 144.