Term | Definition |
Acceleration | change in speed and / or direction of an object’s motion |
Atom | smallest particle of an element that maintains the properties of that element |
Atomic mass | average mass of one atom of an element (from particles in the nucleus) |
Atomic number | the number of protons in the nucleus of an atom; used to determine an element's position in the Periodic Table |
Balanced chemical equation | the numbers of atoms of each element are equal in the product(s) and reactants of a chemical equation |
Balanced force | equal and opposite forces on an object that result in no change in position, direction, or motion; net force equals zero |
Chemical change | the formation of a new substance with different properties; cannot be undone by physical means |
Chemical equation | a representation of a chemical reaction by symbols and numbers |
Chemical formula | a representation of a substance in which the elements are represented by their symbols and subscripts represent the number of atoms of each element |
Chemical property | a characteristic of a substance that describes how it combines with other substances to form new ones |
Chemical reaction | a change caused by the interaction of two or more substances (reactants) resulting in the formation of new substances (products) |
Coefficient | the number placed in front of a chemical formula in a chemical equation; represents the number of molecules of that substance |
Continental drift theory | Alfred Wegner’s explanation of continents slowly moving and changing their positions relative to one another |
Contour intervals | difference in elevation between any two contour lines on a topographic map |
Contour lines | map symbol showing shape and / or change in elevation on a topographic map |
Electrical charge | a property of a subatomic particle; positive (protons), negative, (electrons), or neutral (neutrons) |
Electron cloud | the negatively charged space containing electrons that surrounds the atomic nucleus |
Electron | a negatively charged particle in the electron cloud surrounding the atomic nucleus |
Groups (families) | the vertical columns on the Periodic Table |
Inertia | tendency of an object to resist change in motion |
Law of action-reaction | for every action, there is an equal and opposite reaction |
Law of conservation of mass | matter is not created or destroyed; only rearranged |
Law of force and acceleration | when an object that has a constant mass is acted upon by a force, the object will accelerate in the same direction as the force applied |
Law of inertia | the tendency of an object to resist change in motion unless acted upon by a force |
Net force | measurement of the total forces exerted on an object |
Neutron | a (neutral) particle with no electrical charge within the atomic nucleus |
Nucleus | the positively charged center of an atom containing the protons and neutrons |
Periodic Table | a conceptual model in which the elements are organized according to their properties; often displayed as a chart |
Periodic trend | a regular variation of certain characteristics of elements to increase or decrease along a period (row) or group (column) of the Periodic Table of elements |
Periods | the horizontal rows on the Periodic Table |
Physical property | property of matter that can be observed without changing the composition or identity of the matter |
Plate tectonic theory | the outer most layer of the Earth (lithosphere) is divided into contiguous sections (plates) that move relative to each other causing continental drift, seafloor spreading, and the formation of major physical features of the Earth’s surface |
Precipitate | the formation of solids from a solution |
Product | substance(s) resulting from a chemical reaction |
Proton | a positively charged particle within the atomic nucleus; used to identify an element |
Reactant | substances that are combined and changed during a chemical reaction |
Reactivity | tendency of a substance to undergo chemical changes in a system |
Speed | distance traveled by an object in a given amount of time |
Subatomic particle | a particle smaller than an atom, such as a proton, neutron, or electron |
Subscript | the number written to the right and slightly below an element in a chemical formula; represents the number of atoms of an element present in a chemical formula |
Topographic maps | map showing the shape and elevation of the land surface using contour lines |
Topography | the shape of the Earth’s surface and the way its physical features are arranged, especially in terms of their positions and elevations |
Unbalanced force | unequal forces on an object that may result in a change in position, direction or motion; net force does not equal zero |
Valence electrons | electron(s) located in outer energy level (electron shell) |
Velocity | a measurement of an object's speed and direction |
Yield | the quantity of product formed as a result of a chemical reaction |