Periodic Classification of Elements — Science STD 10 — Question

Which element has:

1. Two shells, both of which are completely filled with electrons?
2. The electronic configuration 2, 8, 2?
3. A total of three shells, with four electrons in its valence shell?
4. A total of two shells, with three electrons in its valence shell?
5. Twice as many electrons in its second shell as in its first shell?