Question

The atomic numbers of elements X, Y and Z are 19, 21 and 25 respectively. The number of electrons present in the M-shell of these elements follow which order

Answer 1

Answer:

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Explanation:

X-19: 1s

2

,2s

2

2p

6

,3s

2

3p

6

4s

1

, here M shell is 3rd energy level which contain 8 electrons 3s

2

3p

6

Y-21: 1s

2

,2s

2

2p

6

,3s

2

3p

6

4s

2

3d

2

, here M shell indicates 3rd enegy level which contain 9 electrons 3s

2

3p

6

3d

1

Z-25: 1s

2

,2s

2

2p

6

,3s

2

3p

6

4s

2

3d

5

, here M shell indicates 3rd energy level which contain 13 electrons 3s

2

3p

6

3d

5

So, here Z contains more electrons in M shell than Y and than X. So the order is Z>Y>X.