What's the next in the series?

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

Solve this riddle by finding the odd one out from the rest.

What runs around the whole yard without moving?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

What is the coolest letter in the alphabet?

There were five men at church, and it started raining while they were outside. The four that ran still got wet, but the one that was still stayed completely dry. Why did he stay dry?

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?