[jadelamlam]

In the space,as there is no air pressure,water has a very low b.p. and it boils.
When we put a ball in container and remove all the air in it,now it is vacuum and no air exists in the container.
So there should be no air pressure and the ball should boil immediately.In fact it doesn't,why?

[vmelkon]

Ball?
What is the ball made of? What is the state of matter of the ball? solid liquid or gas?

[Arkcon]

In the space,as there is no air pressure,water has a very low b.p. and it boils.

Do you mean outer space?  In which case, your premise is wrong, water doesn't boil, it freezes, due to low temperature.  This was notable during the ill-fated Apollo 13 mission:  the astronauts were venting their fluid waste, and the expanding cloud of ice crystals interfered with radar tracking, and they were asked to stop doing that.  Not a fun prospect when you're lost in space in a malfucntioning craft.

When we put a ball in container and remove all the air in it,now it is vacuum and no air exists in the container.

You can't perfectly evacuate anything in the laboratory.  However ...

So there should be no air pressure and the ball should boil immediately.In fact it doesn't,why?

Lowering air pressure definitely reduces boiling point.  How low the boiling point becomes is determined by how good the vacuum is.

[jadelamlam]

Thx for your reply.
That means the ball will change into gas if it is placed in a container at room temperature with no air particles inside?(if the b.p. of ball is less than the room temp),and how to determine the b.p. of a substance in vacuum?