What's the next in the series?

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

Next Number in the Series,

5, 16, 49, 104, ?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

Can you find out the number that should replace the question mark with a valid reason?

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

Can you spot the hidden girl in the picture below?

A thief enters a store and threatens the clerk, forcing her to open the safe. The clerk says, “The code for the safe is different every day, and if you hurt me you’ll never get the code.” But the thief manages to guess the code on his own. How did he do it?