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Intro to Chemistry
Intro to Chemistry (2015)
Term | Definition |
---|---|
atom | The smallest unit of matter. |
molecule | It is made of 2 or more atoms held together by bonds. (Ex. CO2, C6H12O6, NaCl, O2…) |
element | A substance that consists of only one type of atoms like C or Mg or O2. It cannot be broken down by chemical reaction. All the known ones are found in the Periodic Table. |
compound | Substance made of 2 (or more) different types of atoms (like H2O or C6H12O6 - but not O2) |
bond | The attraction (force) that holds atoms together to make molecules. They contain energy! They are "made" of electrons. |
chemical formula | A set of chemical symbols that shows the elements and their proportions - how many of each are in one molecule. |
chemical reaction | A process that rearranges and recombines molecules and atoms, which results in the formation of new chemical substances. |
reactants | The “ingredients” necessary for a chemical reaction. |
products | What is created or produced after a chemical reaction. |
organic compound | A compound whose molecules contain carbon. Usually has C–H bonds, with carbon bonded to hydrogen. |
enzyme | A compound that helps speed up chemical reactions. In the body, they speed up the digestion (breakdown) of food into nutrient molecules. |
photosynthesis | When green plants use sunlight to synthesize food (glucose) from carbon dioxide and water. 6CO2 + 6H2O (+ light energy) --> C6H12O6 + 6O2 Happens in the chloroplasts. |
cellular respiration | The process by which cells use oxygen to break apart glucose to make energy for living. The energy formed is the compound ATP. C6H12O6 + 6O2 --> 6CO2 + 6H2O + Energy (ATP) It occurs in ALL cells (plant or animal), in the mitochondria. |
Periodic Table | A chart that organizes all the known elements by their chemical properties. Elements in a group (column) have similar properties. Metals are on the left, nonmetals on the right. |
chemical energy | Energy in chemical bonds. Can be released in a chemical reaction or absorbed when a new compound is formed. |
glucose | A simple sugar that is used by cells to make energy (by the cellular respiration reaction!) |
mixture | Two or more elements and/or compounds that are physically mixed, but not chemically combined. (Air, soil, blood are all examples.) |
chemical change | evidence of this can be: release of gas/bubbles, a color change or change in temperature |
atomic number | this number tells you the number of protons in the nucleus of an atom. (it also tells you the number of electrons!) |