Term | Definition |
Atom | The basic unit of matter |
Nucleus | The center of an atom; which contains the protons and neutrons. |
Electron | Negatively charged particle; located in the space surrounding the nucleus. |
Element | Pure substance that consists entirely of one type of atom. |
Isotope | One of several forms of a single element, which contains the same number of protons but different number of neutrons |
Compound | Substance formed by the chemical combination of two or more elements in definite proportions. |
Ionic Bond | Type of bond between atoms in which one or more electrons are transferred from one atom to another. |
Ion | Atom that has a positive or negative charge. |
Covalent Bond | Type of bond between atoms in which the electrons are shared. |
Molecule | Smallest unit of most compounds that displays all the properties of that compound. |
van der Waals forces | Slight attraction that develops between oppositely charged regions of nearby molecules. |
Hydrogen Bond | Weak attraction between a hydrogen atom and another atom. |
Cohesion | Force of attraction between molecules of the same substance - force of attraction allowing molecules to stick to other molecules of the same substance |
Adhesion | Force of attraction between different kinds of molecules - force of attraction allowing a molecule to stick to something else. |
Mixture | Material composed of two or more elements or compounds that are physically mixed together but not chemically combined. Each compound retains its own chemical properties. |
Solution | Type of mixture in which all the components are evenly distributed. |
Solute | Substance that is dissolved in solution. |
Solvent | Substance that does the dissolving in a solution. |
Suspension | Mixture of water and nondissolved material. |
pH Scale | Scale with values of 0 to 14, used to measure the concentration of H+ ions in a solution; a pH of 0 to 7 is acidic, a pH of 7 is neutral, and a pH of 7 to 14 is basic. |
Acid | Compound that forms hydrogen ions (H+) in solution; a solution with a pH of less than 7. |
Base | Compound that forms hydroxide ions (OH-) in solution; a solution with a pH of more than 7. |
Buffer | Compound that prevents sharp, sudden changes in pH |
Monomer | Small chemical unit that makes up a polymer. |
Polymer | Molecules composed of many monomers; makes up macromolecules. |
Carbohydrate | Compound made up of carbon, hydrogen, and oxygen atoms; type of nutrient that is the major source of energy for the body. |
Monosaccharide | Simple sugar molecule. |
Lipid | Macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes. |
Nucleotide | Subunit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base - basic building block/monomer of all nucleic acids. |
Protein | Macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair. |
Amino Acid | Compound with an amino group on one end and a carboxyl group on the other end. Building block/monomer of proteins. |
Chemical Reaction | Process that changes, or transforms, one set of chemicals into another. Mass and energy must be conserved. |
Reactant | Elements or compounds that enter into a chemical reaction |
Product | Elements or compounds produced by a chemical reaction |
Activation Energy | Required energy to start/begin a chemical reaction |
Catalyst | Substance that speeds up the rate of a chemical reaction. |
Enzyme | Proteins that act as a biological catalyst - speed up chemical reactions that take place in cells. |
Substrate | Reactant of an enzyme-catalyzed reaction |