Complete the chart. (remember to enter a 0 if necessary.) atomic number: 19 1s: 2s: 2p: 3s: 3p: 4s: 3d: 4p: 5s:

 The completed  chart   atomic number 19  is as below ,

1S  2

2s 2

2p 6

3s 2

3p 6

4s 1

3d 0

4p 0

5s 0

 Explanation

 According to Aufbau  principle  in ground  state, electrons of atom fill  the  atomic orbital of lowest  energy  level   before  occupying  that of higher energy level .

1s  orbital is of lower  energy and is  filled  first , followed by 2s  orbital , 2p  orbital , 3s orbital, 3p orbital   and finally  4s orbitalS orbital  can hold a maximum of 2  electrons . P  orbital  can hold   a  maximum of 6  electrons  while d  orbital  can  hold a maximum of  of 10 electrons.

Therefore  element  in  atomic number 19  has  1s2 2s2 2p6 3s2 3p6 4s1  electron configuration .

[Ar] 4s1
1s2
2s2
2p6
3s2
3p6
4s1
<3

1. Mass
2. Matter
3. Weight
4. Compound
5. Molecules
6. Atom