Term | Definition |
Matter | Anything that has mass and occupies space |
Atom | the smallest portion of an element |
Nucleus | the center part of an atom that contains protons and neutrons |
Proton | a particle in an atom found in the nucleus that has a positive electrical charge |
Neutron | a particle in an atom found in the nucleus that has no electrical charge |
Electron | a particle in atom that has a negative charge |
Element | substance that cannot be seperated into a simpler substance |
Periodic Table | an orderly arrangement of element based on their atomic numbers |
Atomic Number | an element's position in the periodic table based on (and equal to ) the number of protons it has in its nucleus |
Isotopes | atoms of the same element that have different numbers of neutrons in the nucleus |
Atomic Mass | the mass contained in an element's nucleus, which is equal to the number of protons plus the number of neutrons |
Electron Energy Level | the distance at which electrons travel around the nucleus of an atom |
Chemical Compound | a chemical combinations of two or more atoms or elements |
Chemical Reaction | process that occurs when one substance is changed into another |
Reactivity | an element's ability or tendency to combine with another element |
Chemical Bond | The attractive force between atoms that is formed when atoms transfer or share their electrons
2) a connection made between atom when electrons are attracted, shared, or transferred |
Valence Electrons | the electrons found in the outer energy level of an atom |
Octet Rule | tendency of atoms to gain, lose, or share electrons with other atoms in order to have 8 electrons in their outer energy level |
Electron Dot Diagram | a diagram of an atom that represents its valence electrons as dots around the chemical symbol |
Ionic Bond | a bond formed when elements transfer (gain or lose) electrons |
Ion | an electrically charged ''atom'' that has either gained or lost electrons
2) an atom or molecule that has gained or lost electrons so that it has a positive or negative charge |
Covalent Bond | a bond formed when elements share electrons |
Organic Compound | carbon-compounds that make up living tissue |
Polar Molecule | a molecule that has a partial positive charge one end and a partial negative charge on the other end |
Hydrogen Bond | in the case of water molecules, the weak bond that occurs when the hydrogen in one water molecule is attracted to the oxygen in another water molecule |
Cohesion | the attraction between molecules of the same kind |
Surface Tension | the film-like quality on the surface of a liquid that is caused by the attraction of the liquid molecules to themselves |
Adhesion | the attraction of one type of molecule to a different type of molecule |
Capillary Action | the tendency of a liquid to draw up into a narrow tube due to the liquid's properties of cohesions an adhesions |
Specific Heat | the amount of heat needed to raise the temperature of one gram of a substance one degree Celsius |
Solvent | a substance that dissolves another |
Biological Process | any process that occurs in a living organism, such as muscle movement in animals or photosynthesis in plants |
pH | a measure of the acidity or alkalinity of a substance |
Acid | a solution with more hydrogen ions than hydroxide ions, having a pH less than 7 |
Base | a solution with more hydroxide ions than hydrogen ions; having a pH greater than 7 |
Buffer | a substance that prevents the pH of a solution from changing even if a small amount of an acid or a base is added |