Term | Definition |
matter | anything that takes up space and has mass |
mass | the material that matter is made up of |
volume | how much room/space matter takes up |
density | D=m/v the amount of material/stuff matter takes up within a specific space |
atom | the smallest unit of matter that builds up all matter |
protons | positively charged particles in an atom's nucleus |
neutrons | particles with no charge that accompany protons in the nucleus of an atom |
electron | negatively charged particles that move around rapidly outside of an atom's nucleus and that has an attractive force that bonds atoms together |
Periodic Table | A chart that classifies elements by their physical and chemical properties |
element | makes up all matter in the universe, cannot be broken down, and is the simplest substance. |
periods/rows | The rows that make up the Periodic Table and tell us how many energy levels an element has |
groups or family/columns | The columns in the periodic table that tell us how many electrons are in an atoms outer energy level |
valence electrons | The electrons in an atom's outer energy level |
atomic number | The number of protons in an element, also usually determines the number of neutrons and electrons |
atomic mass | The mass of an element's atoms |
chemical property | The ability a substance has to combine with others to form new ones |
physical property | includes a substance's appearance and state of matter. |
ionic bond | This occurs when elements lose or gain an electron while bonding |
covalent bond | this happens when elements share an electron while bonding |
chemical change/reaction | this occurs when the electron's attractive force bonds two elements together creating a reaction or change |
compound/molecule | two or more elements that combine in a set ratio making a whole new substance |
mixture | two or more substances that are combined, but retain their properties and are not a whole new substance, thus not chemically combined |
Nobel Gases | All of elements in Group #18 that are the most stable elements because they have eight valence electrons |
Halogens | all elements in group #17 they are very reactive with elements in group #1 because they have 7 valence electrons and want to be stable |
Alkali Metals | all elements in group #1- all have only one valence electron and are very reactive |
Metalloids | elements with 3-7 valence electrons between metals and non-metals that can react either way |
Endothermic | a chemical reaction that absorbs energy (decrease in temp) |
Exothermic | a chemical reaction that produces energy (heats up) |