If you say my name, I will no longer exist. What am I?

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.

How can you take 2 from 5 and leave 4?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

What you cannot hold but it is yours?

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

What is the Surname of Barbie Doll?