I have branches, but no fruit, trunk or leaves. What am I?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

81 x 9 = 801. What must you do to make the this equation true?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

If two's company, and three's a crowd, then whats four and five ?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

What begins with T, ends with T, and has T in it?

I am five letter word that is under you.
If you remove my 1st letter, then I am over you.
If you remove my 1st and 2nd letters then I am all around you.

Who am I?

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?