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Chemistry Vocab 2
Term | Definition |
---|---|
Atomic Mass | The mass of an atom, approximately equal to the number of protons and neutrons in the atom. |
Groups | The columns on a Periodic Table that arrange the elements by the number of electrons that are in the outermost shell. |
Periods | The rows in a Periodic Table that classify the elements by the number of electron shells. |
Metals | Most elements are metals. They are typically solid, shiny, malleable, and good conductors of heat and electricity. |
Non-Metals | Elements typically not shiny, usually a gas or brittle solid, not malleable, and poor conductors of heat and electricity. |
Metalloids | Elements that have properties of both metals and non-metals; sometimes referred to as semiconductors. |
Noble Gasses | Unreactive non-metals in Group 18 of the Periodic Table. |
Electron Shell | A specific area where electrons of the same energy level are found. |
Valence Electrons | The electrons in the outermost energy level of an atom that influence how an element will react with other substances. |
Energy Level | A state in which matter can exist with a quantifiable amount of energy and distinct from other states with different amounts of energy. |
Reactivity | Rate at which a chemical substance tends to undergo a chemical reaction; significantly influenced by valence electrons of the reacting substances. |
Outermost Electron Cloud | The area surrounding the nucleus of an atom where the electrons are found. |
Net Charge | The sum of negative and positive charges. |
Ions | Form as a result of the loss or gain of electrons and are identified by the overall net charge. |
Chemical Reactions | The process by which one or more substances change to produce one or more different substances |
Precipitate | A solid that is deposited from a solution |
Endothermic | A process that absorbs heat |
Exothermic | A process that releases heat |
Chemical Formula | A shorthand notation that uses chemical symbols and numbers as subscripts to represent the type and number of atoms that are present in the smallest unit of the substance. |
Reactants | A substance that takes part in and undergoes change during a reaction |
Products | Substances produced during chemical reactions |
Coefficient | A number placed in front of a chemical symbol or formula in order to balance the equation |
Subscript | A number written below and to the right of an atomic symbol in a chemical formula that shows the number of a specific type of atom present |
Balanced Equation | A symbolic representation of a chemical reaction in which both sides of the equation contain equivalent numbers of atoms of each element. The mass and charge must be balanced on both sides of the reaction. |