Term | Definition |
atoms | basic unit of a chemical element |
elements | a substance that cannot be broken down by chemical mean |
nucleus | The core or the central part around which other parts are grouped or gathered. |
electron shells | a grouping of electrons surrounding the nucleus of an atom |
protons | a stable subatomic particle with a positive charge |
neutrons | a subatomic particle of about the same mass as a proton but without an electric charge |
electrons | a stable subatomic particle with a charge of negative electricity |
atomic number | the number of protons in the nucleus of an atom |
atomic mass | the mass of an atom of a chemical element expressed in atomic mass units, equal amount to protons and neutrons. |
valance electrons | the outer shell of an atom which can combine with other atoms to form molecules |
speed | refers to "how fast an object is moving." |
velocity | refers to "the rate at which an object changes its position." |
acceleration | increase in the rate or speed of something |
force | a push or a pull, strength or energy as an attribute of physical action or movement |
balanced force | the forces pushing (or pulling) an object in one direction are the same size as the forces acting in the opposite direction. |
unbalanced force | refers to a force that together can equal a certain number and will make a change of the object's motion. |
direction | a course along which someone or something moves. |
Newton's 1st law | an object at rest stays at rest. an object in motion stays in motion unless force is acted upon it. |
Newton's 2nd law | sum of the forces on an object is equal to the total mass of that object multiplied by the acceleration of the object |
Newton's 3rd law | a force equal in magnitude and opposite in direction to that of the first body. |