Physics-Thermal Energy and Radioactivity

Temperature

average KE of particles that make up the object

Thermal Energy

sum of kinetic and potential energy of particles that make up an object

Heat

Heat

energy transferred between objects due to temp. diff.

Specific Heat

amount of heat needed to raise the temp of 1 kg of a material by 1 degree celsius

Conduction

transfer of thermal energy via contact (collisions between particles in matter)

Convection

heat transfer through movement of fluid

Radiation

heat transfer through EM waves

Kinetic theory

-all matter is composed of particles (ions, molecules, atoms)

-particles are in constant random motion

-particles collide with each other and walls of container

-energy that particles lose is negligible

melting point

temp at which a solid becomes a liquid

Heat of fusion

energy required to change a solid to liquid at melting point

Boiling point

temp at which pressure of vapor in liquid=pressure acting on surface

Heat of vaporization

amount of energy a liquid needs to become gas at its boiling point

sublimation

solid changing to a gas

plasma

matter that has enough energy to overcome attractive forces between particles and atoms

Thermal expansion

increase in size of a substance when temp is increased

isotope

nuclei with the same number of protons but diff numbers of neutrons

Strong force

Force that causes protons and neutrons to be attracted to one another

Alpha particle

particle with 2 protons and 2 neutrons

Beta particle

electron emitted when a neutron decays into a proton

transmutation

changing one element into a diff element

What happens during alpha decay?

a nucleus loses 2 protons and 2 neutrons. new element has atomic number that is 2 less than original element

What happens during beta decay?

Neutron emits electron, become a proton. new element has atomic number 1 greater than the original