What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Replace the question mark with the number below given a simple math problem.

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

What do you see in the image below

If six children and two dogs were under an umbrella, how come none of them got wet?

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.