When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

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

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Why is a river so rich ?

I taste better than I can smell. Who am I?

What is more useful when it is broken?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

You can see three almost identical images below. Can you spot the odd one out from them?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?