What does below chemistry rebus means?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

If all Goats are Sheep and all Sheep are Deers, are all Deers Goats ?

An evil man kidnapped someone and made them take one of two pills. One was harmless, but the other was poisonous. Whichever pill the victim took, the kidnapper took the other one. The victim took their pill with water and died. The kidnapper survived. How did the kidnapper get the harmless pill?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

There is something which is always coming but never arrives?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.