ABCDEFGIKLMNOPRSTUVWX air resistance 1. The drag force of air. 2. The resistive force acting on a moving body by the air. alpha decay Radioactive decay in which the nucleus releases an alpha particle. alpha particle A positively charged particle, that cannot be distingushed from a helium atom. altitude The vertical elevation of an object above a surface of a planet or natural satellite (as in sea level or land) amplitude The maximum height of a given wave motion. atom "The smallest unit of an element composed of a nucleus (the center region that contains protons and nuetrons) and electrons which orbit the nucleus. beta decay Radioactive decay in which the nucleus releases either a negatively or a positively charged electron (positron). beta particle An electron (or positron) released in beta decay from a radioactive isotope. biology The science of life and living things. It studies the structure, function, growth, origin, and evolution of living organisms (plants, animals, etc.). capacity The maximum ability to perform or produce; potential. chemical bond Forces that hold atoms together. The bonds are formed by either sharing electrons or by the transferring of elections. chemical energy 1. The energy that is used to hold the substance together by forming chemical bonds. 2. The kind of energy that is trapped in a substance and can be freed by a chemical reaction. chemical reaction The process, which causes a change in the chemical properties of the substances involved. chromosome This part of the cell stores chromatim, which is like a package that contains the genetic code. cosmic radiation High-energy type wave or particle radiation coming from deep space. Cosmic rays are the most penetrating and dangerous radiation types. distinguish To make different or noticeable. dna 1. DNA is short for deoxyribonucleic acid. 2. Any of various nucleic acids that are usually the molecular basis of heredity, are localized especially in cell nuclei, and are constructed of a double helix. drag force The resistant force acting on a moving body which occurs when resistance is present. elasticity 1. The degree of being elastic. 2. Returning to an initial form or state after a temporary deformation has occurred. electric field A refion in which forces act on any electric charge present. electrical energy Energy due to the motion and organization of charged particles. electromagnetic radiation The emission and propagation of electromagnetic energy from a source including radio waves, heat rays, light, and X-rays. electromagnetic spectrum 1. The entire range of electromagnetic radiation ordered according to their frequencies and energy. 2. In the order of decreasing frequency, cosmic rays, gamma rays, x-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, and radio waves. electromagnetic wave A wave composed of two mutually dependent, mutually perpendicular crosswise lying waves of electric and magnetic fields. electron Negatively charged particle orbiting around the nucleus. endoplasmic reticulum This organelle is made up of two parts: smooth ER and rough ER. The purpose of the rough ER is to collect proteins. The proteins collected are used either inside or outside the cell. The smooth ER, which is slightly tubular in shape, creates something called steroids. Smooth ER also stores ions. These ions are stored so the cell can keep a correct level of nutrients. Remember, smooth ER stores and contains and rough ER collects. energy The ability or capacity to produce change. fission "The nuclear reaction in which a relatively heavier nucleus divides into two or more lighter nuclei with the simultaneous release of energy. In this process a large amount of energy is released. flagella This is a specialized tail-like structure used to help the cell move. force 1. The ability to cause change or energy transfer. 2. The capacity to produce energy transfer. frequency The number of times a wave vibrates or event occurs within a specific unit of time (second, hour etc.) fusion The nuclear reaction in which two or more relatively light nuclei come together to form a heavier one. In this process a large amount of energy is released. gamma ray Invisible radiation with wavelength starting from about ten nanometers. A very energetic electromagnetic radiation that can penetrate even thick layers of lead. gene a specific sequence of nucleotides in DNA or RNA that is located on a chromosome and that is the functional unit of inheritance controlling the transmission and expression of one or more traits. gravitational acceleration The change in speed that is a result of the gravitational force. gravitational force The force that occurs as a result of the attraction between objects due to their masses. infared Invisible radiation with wavelength ranging from about 750 nanometers to 1 millimeter. This is radiation that heat gives off. ionizing radiation High-energy type wave or particle radiation capable of producing ionization in substances through which it passes. kinetic energy Energy due to the movement of objects with mass. law of conservation of energy A principle that cannot be violated by any physical process, it states that; energy can neither be created nor destroyed, it only changes in form. magnetic field Strength of the interaction due to the motion of charged particles. mass The measure of an objects resistance to changes in either the speed or direction of its motion. microwave Invisible radiation that is part of the elctromagnetic spectrum with wavelength ranging from about one millimeter to one meter. This type of radiation is used in heating foods with microwaves. mitochondria These are very tiny organelles, yet they are the POWERHOUSE of the cell. Their job is to break down food molecules so the cell has energy to live. molecule A group of atoms held together by chemical forces. Human cells are examples of molecules. nanometer One billionth (exponential form: 10-9) of a meter. A unit used to measure subatomic (objects that are smaller then atoms) objects. neutron Electrically neutral nuclear particle in the nucleus of an atom. nucleus The positively charged heavy core region of an atom, made of protons and neutrons. oscillation A back and forth change; vibration. parallel Lines or planes that have no intersection in any direction. particle radiation The emmission of a particle by an atom. Alpha and beta decay are examples of particle radiation. penetrate What is going to happen to Debra's head if she comes into my office again toda!!! perpendicular 1. Intersecting at or forming right angles 2. At right angles photon The little packages of electromagnetic energy that can be particles and/or waves. plasma membrane This holds the cell together. It keeps all the pieces, like the organelles, inside. The membrane also controls what goes in and out of the cell. It acts kind of like a crossing guard. potential energy Energy that is stored; having the possibility rather than the actual ability to produce change. pressure Force applied over an area. propagate To cause or spread to a larger area or number. proton Positively charged nuclear particle in the nucleus of an atom. radiation Energy radiated or transmitted in the form of particles as rays or waves. radio wave Invisible radiation with wavelength ranging from about 3 millimeters to about 20 meters. They are used in radio transmission. This radiation is the least dangerous and least energetic. radioactive decay The spontaneous nuclear reaction in which a less stable nuclei becomes more stable by releasing several particles and waves solar energy Energy coming from the sun (in the form of electromagnetic radiation). sound waves Longitudinal pressure waves in any material medium regardless of whether they constitute audible sound (earthquake waves and ultrasonic waves are sometimes called sound waves). spectrum A complete range of things. stable atoms 1. Atoms that are not likely to undergo radioactive decay. 2. Atoms that have a balanced number of proton to neutron ratio tumor The term applied to any collection of abnormally growing cells. Tumors that are cancerous are termed malignant; those that are not cancerous are termed benign. ultraviolet Invisible radiation that is part of the electromagnetic spectrum with wavelengths ranging from about 4 nanometers to about 380 nanometers. This radiation is what the sun produces. unstable atoms 1. Atoms that are likely to undergo radioactive decay. 2. Atoms that have imbalanced number of proton to neutron ratio. vacuum 1. A part of space that is totally absent of matter. 2. An empty space. 3.A state of emptiness; a void. vibration 1. A periodic motion of the particles of an elastic body or medium in alternately opposite directions from the position of equilibrium when that equilibrium has been disturbed. 2.The action of vibrating; the state of being vibrated or in vibratory motion. visible light Visible radiation with wavelength ranging from about 400 nanometers to 700 nanometers. This radiation is the colors that you see, including all the colors of the rainbow. wave energy The total energy of a wave. wavelength The distance between two consecutive peaks of a wave. x-ray Part of the electromagnetic spectrum with wavelength ranging from about 0.01 nanometers to 10 nanometers. X-rays (man-made) are used in x-ray machines that help doctors see inside our bodies. ABCDEFGIKLMNOPRSTUVWX