Internal energy

Question 1

What is internal energy?

Answer 1

The energy stored by particles in a substance.

Question 2

What is internal energy made up of?

Answer 2

The total kinetic and potential energy of all the particles in a substance- this is caused by their individual motions and positions.

Question 3

What are bonds?

Answer 3

The forces that hold particles together.

Question 4

How do bonds effect the melting and boiling points of a substance?

Answer 4

The stronger the bonds, the higher the melting and boiling points of a substance, and vice versa.

Question 5

What happens when a substance is heated?

Answer 5

• If it’s temperature rises, the kinetic energy of its particles increase
• If it melts or boils, the potential energy of its particles increase

Question 6

What are the forces of attraction like in a solid?

Answer 6

They are strong- these forces bonding the particles in fixed positions.

Question 7

What are the forces of attraction like in a liquid?

Answer 7

• The forces of attraction still exist between particles, but have more kinetic energy than a solid
• They are not strong enough to hold the particles together in a fixed structure

Question 8

What are the forces of attraction like in a gas?

Answer 8

They have no effect on the particles, as they are moving so fast.