Matter and Energy Concepts

Matter and Energy

• Matter is anything that has mass and takes up space.
• Radiation is the emission of energy as electromagnetic waves or subatomic particles.
• Energy is the capacity to do work.
• Ionizing radiation has enough energy to remove tightly bound electrons from atoms, creating ions.
• Physics is the natural science that studies matter, its motion and behavior through space and time.
• Radiation physics is the study of the physical aspects of radiation.

Types of Energy

• Kinetic energy is the energy an object has due to its motion.
• Potential energy is the energy stored in an object due to its position or state.

Forms of Energy

• Chemical energy is stored in the bonds of chemical compounds.
• Electrical energy results from the movement of charged particles.
• Thermal energy is related to the temperature of an object.
• Nuclear energy is released during nuclear reactions.

Structural Levels

• A compound is a substance formed when two or more chemical elements are chemically bonded together.
• An element is a pure substance consisting of one type of atom.
• A molecule is two or more atoms chemically bonded together.
• An atom is the smallest unit of matter.
• The nucleus is the positively charged center of an atom, containing protons and neutrons.
• Nucleons are protons and neutrons in the nucleus.
• Electrons are negatively charged particles orbiting the nucleus.

Additional Terms

• A neutral atom has an equal number of protons and electrons.
• An ion is an atom that has lost or gained electrons and has a charge.
• An isotope is atoms of the same element with different numbers of neutrons.
• Atomic number is the number of protons in an atom.
• Mass number is the sum of protons and neutrons in the nucleus.
• Atomic weight is the average mass of atoms of an element.

Bonding

• Ionic bonding is the transfer of electrons from one atom to another, creating ions.
• Covalent bonding is the sharing of electrons between atoms.

Composition of Rays

• Alpha rays are helium nuclei.
• Beta rays are high-energy, high-speed electrons or positrons.
• Gamma rays are high-energy, electromagnetic radiation.

Wavelength and Frequency

• Wavelength is the distance between successive crests of a wave.
• Frequency is the number of waves that pass a point in one second.

Units of Measurement

• Roentgen (coulomb/kilogram): measures exposure to ionizing radiation.
• Rad (Gray): measures absorbed radiation dose.
• Rem (sievert): measures biological effect of ionizing radiation.
• Curie (Becquerel): measures radioactivity.

Atom Structure

• Understanding the historical progression of atomic models (from Dalton's solid sphere to the quantum mechanical model).
• Electron capacity in shells: the maximum number of electrons in each shell can be calculated using 2n², where n is the shell number.
• Outer shell electrons: the outermost shell can hold a maximum of 8 electrons.

Radioactive Terms

• Radioactive disintegration/decay: the process by which an unstable atomic nucleus loses energy by radiation.
• Nuclide: a species of an atom with a specific number of protons and neutrons.
• Half-life: the time taken for half of the radioactive nuclei in a sample to decay.

Ionizing Radiation

• Particulate radiation: alpha particles (helium nuclei), beta particles (electrons or positrons).
• Electromagnetic radiation: gamma rays and x-rays.

Test Review Questions (sample)

• Proton charge: positive
• Neutron charge: neutral
• Electron charge: negative
• Number of protons in an oxygen atom: 8
• Number of protons in a hydrogen atom: 1 and other questions.

Additional Concepts

• Fomites (something that virus or bacteria travels on like a book or key).
• Vectors (transmit infection from one host to the next).
• Different types of energy (electromagnetic, thermal, ionizing).