chem unit 3

Vocabulary flashcards covering protons and neutrons based on the nucleus lecture notes.

Proton ($p^+$)

A particle with a positive charge that determines the identity of the element.

Neutron ($n^0$)

A particle that is the same size as a proton, has a neutral charge, and serves as the "glue" that holds the nucleus together.

Electrons (e-)

Very small particles that have a negative charge

Alpha Particles

• a helium nucleus

• Symbol= 4/2 He

Beta Particles

-a high speed electron that is emitted from the nucleus

-symbol -0/1 e

Gamma ray

• a high energy particle of light

• Symbol 0/0 Y

Positive production

• a particle with the same mass of an electron but with a positive charge

• Symbol = 0/1 e

Describe the charge and density of the atomic nucleus

Nucleus - positively charged and extremely dense

what was Democritus contribution to atomic theory

The first to suggest the idea of an atom

Plum pudding model

The atom consists of a pudding of positive charge with the negatively charged electrons randomly distributed in it.

Cathode ray experiment . What subatomic particle was discovered?

An experiment where electric current was passed through gases at a low pressure. It showed a beam of light seen traveling from the cathode to the anode.

Gold foil experiment. Who performed this experiment? What where the conclusions

Shot an alpha particle through a thin piece of gold foil

What particle make up the nucleus of the atom

Positively charged and extremely dense

Isotopes

An atom that has the same number of protons but a different number of neutrons

Mass number

The total number of protons an neutrons in the atom

Atomic number

The number of protons that are found in an atom

Nuclear fusion

The process where two light nuclei combine together to form a larger nuclei

When a nuclear reaction is critical it means?

The nuclear reaction is under control

What are the consequences is a nuclear reaction is not critical

Produce more energy than can be continued

What is a chain reaction?

A reaction where a neutron from a fission even causes another fission event

What is the force between protons and neutrons that are close together called?

Nuclear force

What are the factors that determine the biological damage done by radiation?

Types of radiation

Which form of radiation has the greater penetrating power

Greatest - gamma

Least- alpha

Which form of radiation has the greatest ionizing ability? The least?

Greatest- alpha

Least- gamma

Arrange alpha particles, gamma, and beta based on increasing size

Gamma ray < beta < alpha

Fuel rod

Metal rods that contain 3% enriched uranium-235

Moderator

A substance that surrounds the fuel rods that slow down neutrons

Control rods

Rods that composed of elements that can absorb neutrons

Water

Circulated in the reactor to absorb the heat produced in the fission reactor

How does a nuclear reactor produce energy?

A nuclear reactor uses the heat produced steam which can be used to create electricity

Define half life

Time it takes for half of a radioactive sample of decay