Question

Science 7 Grade 7. Can anyone please help me answer these science questions?

I need the answers soon as possible.

Thermal expansion in a balloon occurs because _____.

the gas cools off and causes the size of the balloon to change
when the gas heats up, the particles move closer together
when a gas is heated, the particles hit the walls of the container with greater force
when the gas cools, the particles move closer together

______________ is a way thermal energy is transferred.
Fill in the blank ?


a cellphone battery is what type of energy form?
a piston in an engine is what type of energy form?
the choices are :
nuclear, radiant ,sound, thermal, electric, mechnical

Answer 1

a cellphone battery is a electrical energy
and a piston in an engine is an thermal energy

Answer 2

Thermal expansion in a balloon occurs because when the balloon is heated up, the gas molecules will move faster and in greater distance so when if they move faster then they will hit the wall with greater force, will result to expansion.

conduction, convection and radiation are the ways that thermal energy is transferred.

a cellphone battery is an electrical energy, then piston in an engine is mechanical energy