Chemistry Unit 3

a helium nucleus that is emitted from a radioactive atom.

alpha particle

a high speed electron that is emitted from a radioactive atom. Neutron is transformed into a proton

beta particle

a high-energy photon (particle of light) that is emitted from a radioactive nucleus. They have zero mass

gamma particle

paper

What stops alpha?

the emission of alpha particles, beta particles, or gamma rays from the nucleus of an atom

nuclear radiation

the number of protons and neutrons in the nucleus of an atom

mass number

the number of protons in the nucleus of an atom.

atomic number

Atoms that have the same number of protons (and are therefore the same element) but different numbers of neutrons.

isotope

an "ordinary" element: does not break down and does not emit particles or rays.

stable isotope

breaking a large nucleus into smaller nuclei.

This is what releases the energy in nuclear reactors and atomic bombs.

fission

Smashing smaller nuclei together to form larger nuclei. This releases even more energy than nuclear fission.

fusion

carbon dating.

This isotope is used to estimate the age of living things years after they die. What is this dating technique called?

metal

What stops beta radiation?

lead or concrete

What stops gamma radiation?

when one fission causes another and another

chain reaction

fusion

type of radioactive reaction found in the sun

fission

type of nuclear reaction found in nuclear power plants

beta decay

What type of decay occurs when Pascalium-234 turns to uranium-234?

alpha decay

What type of decay occurs polonium-214 decays to lead-210?

gamma decay

What type of decay occurs between polonium-210 to polonium-210?

smallest subatomic particle with a mass of 0, has a negative electrical charge, is found outside the nucleus in the electron cloud

electron

Center of the atom, contains almost all of the atomic mass, contains protons and neutrons

nucleus

Subatomic particle with a positive charge, a mass of 1 AMU, found in the nucleus, determines the identity of an atom

proton

Subatomic particle with no charge, a mass of 1 AMU, and is found in the nucleus.

neutron

Area outside the nucleus that contains electrons. Makes up most of the volume of an atom

electron cloud (energy levels, electron shells)

Determined by comparing the number of protons (+) and electrons (-). Atoms have a neutral charge when #protons = #electrons. Assume atoms are neutral unless you have evidence that indicates a positively or negatively charged atom

electrical charge of an atom

the smallest particle of an element, made of protons, neutrons, and electrons

atom

The mass of an atom, equal to the number of protons + the number of electrons in the atom.

Atomic Mass

The number of protons in the nucleus of an atom

Atomic Number

Forms as the result of the loss or gain of electrons and are identified by the overall net charge of the atom

Ion

Chart that organizes all known elements in order of increasing atomic number

periodic table

columns on the periodic table, same reactivity, same # of valence electrons

group/family

rows on the periodic table, same # of electron shells

periods