What does below chemistry rebus means?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

Jack was having a candle light dinner with his girlfriend. Suddenly a cold gush of wind entered through the open window and three of the ten candles were extinguished. Assuming that none of the other candles were extinguished.

How many candles are they left with in the end ?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

Can you spot the man between the coffee bean in the picture below ?

I start and end with 500 and carry a 5 in my heart. But I require the first letter and the first number to be complete. I am the name of a King.

Who am I ?

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

What is the last thing you take off before bed?

Can you place six X (crosses) in below board without making three in a row in any way ?