Which of the following statements concerning periodic table "position" and electron configurations is correct

Question

1. The 3p subshell begins filling at element 13.
2. The 4s subshell becomes completely filled at element 19.
3. The third shell becomes completely filled at element 18.
4. More than one of the above answers are correct.
5. None of the above answers are correct.

Answer 1

3.

Answer 2

a nitrogen b helium c idk wtf u wrote there d lithium in case you stick to those down you have your answer exept for helium, pass to berillium for that one, they simply placed helium the place that's because of the fact its a noble gas, all the different noble gases lead to p6