Consider an element whose outermost electron is 3d^10 4s^2 4p^x?

Question

1. The group number will equal (10 + 2 + x) True or False

2. The hardest, densest metals are found in which block, s,p,d or f?

3. Name the most chemically active halogen.

4. Write its electron configuration

5. Write the configuration of the most-stable ion this element makes.

Answer 1

If you're in the US, 1 is true, otherwise not, eg in the UK.
Transition metals are the most dense.
Fluorine, 1s2, 2s2, 2p5 is the most reactive halogen.
Fluoride ion is 1s2, 2s2, 2p6.