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Question
An atom of an element contains 35 electrons and 45 neutrons. Deduce
- the number of protons
- the electronic configuration for the element
- All the four quantum numbers for the last electron
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Solution
An element X contains 35 electrons, 45 neutrons
- The number of protons must be equal to the number of electrons. So the number of protons = 35.
- Number of electrons = 35. So the electronic configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5.
- The last electron i.e. 5th electron in 4p orbital has the following quantum numbers. n = 4, l = 1, m = +1, s = `+1/2`
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