Melting and boiling temperatures of different substances

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To determine which substance is a gas at 25°C, one must compare the melting and boiling points of each substance. A substance is a gas at a given temperature if its boiling point is higher than that temperature and its melting point is lower. In this case, substance A has a melting point of -219°C and a boiling point of -183°C, indicating it is a gas at 25°C. Therefore, the correct answer is substance A. Understanding the phase changes of substances is crucial for solving such problems.
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Hi all
I am sorry for the double post, I just found out there is a homework help place here..
I have this question in a practice physics exam:
The table lists melting and boiling temperatures of 4 different substances, A,B,C,D..
The question is "Which substance is a gas at 25 C?"

Substance Melting point /C Boiling point/C
A -219 -183
B -7 58
C 98 890
D 1083 2582

I have no idea how to get the answer.. Can someone please explain how..
Thanks!
 
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Welcome to PF!

riyada said:
The table lists melting and boiling temperatures of 4 different substances, A,B,C,D..
The question is "Which substance is a gas at 25 C?"

Substance Melting point /C Boiling point/C
A -219 -183
B -7 58
C 98 890
D 1083 2582

Hi riyada! Welcome to PF! :smile:

A solid melts at its own melting point, and becomes a liquid.

A liquid boils at its own boiling point, and becomes a gas.

The question gives you the melting point and the boiling point of four substances. :smile:
 
Beautifully answered!
Its "A"..
Thanks a MIL!
 

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