Can you replace the question mark with the correct number?

I am eight letters long - "12345678"
My 1234 is an atmospheric condition.
My 34567 supports a plant.
My 4567 is too appropriate.
My 45 is a friendly thank-you.
My 678 is a man's name.

What word am I?

What is always in front of you but can’t be seen?

Your job is to measure 45 minutes if you have only two cords and matches to light the cords.

1. The two cords are twisted from various materials, so their different segments can burn at different rates.
2. Each cord burns from end to end in exactly one hour.

Describe your way of measuring the 45 minutes.

What has a bottom at the top?

Decode the movie name from the below picture?

What number should come in place of the question mark below?

What is the fastest way to double your money?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

You have to put a letter on the following to make it a meaningful word. The only challenge is that you can't use 'E'.

S E Q U E N C _