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Chemistry Midterm1-8
Chemistry Midterm1-8 Sierra Hansen
Term | Definition |
---|---|
Chemistry | The science of materials and the changes that these materials undergo. |
Scientific Method | Systematic process for studying nature that involves observations, hypotheses, and experiments. |
Measurment | A quantitative observation. |
Natural Law | Statement that summarizes generally observed behavior. |
Atom | Fundamental unit of which elements are made. |
Molecule | A collection of atoms bonded together that behave as a unit. |
Elements | Substances containing only one type of atom. |
Physical Change | Chang that does not affect the composition of a substance. |
Chemical Change | Change in which a substance becomes a different substance. |
Mixture | A substance with a variable composition. |
Alloy | A mixture of elements that has metallic properties. |
Pure Substance | Either pure element or a compound. |
Law of constant composition | A given compound always contains elements in exactly the same proportion by mass. |
Compound | A substance made of two or more different elements joined together in a specific way. |
Electron | A negatively charged subatomic particle. |
Nucleus | The relatively small, dense center of positive charge in an atom. |
Proton | A positively charged subatomic particle located in the atomic nucleus. |
Neutron | A subatomic particle with no charge located in the atomic nucleus. |
Isotopes | Atoms with the same number of protons but different numbers of neutrons. |
Atomic Number | The number of protons in the nucleus of a given atom. |
Mass Number | The total number of protons and neutrons in the nucleus of a given atom. |
Group | A vertical column of elements on the periodic table. |
Diatomic molecule | A molecule composed of two atoms. |
Distillation | A separation process that depends on the different boiling points of the substances. |
Filtration | Separation of a solid from a liquid by using filter paper. |
Homogeneous mixture | A mixture that is the same throughout. |
Solution | A homogeneous mixture. |
Heterogeneous mixture | A mixture containing regions with differing properties. |
Solid | Substance with a fixed shape and volume. |
Liquid | Substance with a definite volume that takes the shape of it container. |
Gas | Substance with no definite shape or volume. |
Physical Property | Characteristic of a substance that can change without the substance's becoming a different substance. |
Chemical Property | Characteristic that describes the ability of a substance to change to a different substance. |
Ion | An atom or group of atoms that has a positive or negative charge. |
Cation | A positively charged ion. |
Anion | A negatively charged ion. |
Ionic compound | A compound that results when a metal reacts with a nonmetal to form cations and anions. |
Binary ionic compound | A two element compound consisting of a cation and an anion. |
Polyatomic ions | An ion consisting of two or more atoms bound together. |
Oxyanion | A polyatomic ion containing at least one oxygen atom and one or more atoms of at least one other element. |
Acid | A substance that produces hydrogen ions (h+) in solution; a proton donor. |
Unit | The part of the measurement telling us the scale being used. |
Volume | The amount of three- dimensional space occupied a substance. |
Mass | The quantity of matter in an object. |
Significant figures | The certain digits and the first uncertain digit of a measurement. |
Conversion factor | An ratio used to convert from one unit to another. |
Dimensional Analysis | The process of using conversion factors to change from one unit to another. |
Density | The mass of a substance per given volume of that substance. |
Specific gravity | The ratio of the density of given liquid to the density of water at 4 C. |
Atomic mass unit | A small unit of mass equals to 1.66 X 10 -24. |
Average atomic mass | The weighted average of the masses of all the isotopes of an element. |
Mole | The number equal to the number of carbon atoms in exactly 12 grams of pure 12C Avogadro's number. One mole represents 6.022 X 10 23 units. |
Avogadro's number | The number of atoms in exactly 12 grams of pure 12C, equal to 6.022 X 10 23. |
Molar Mass | The mass in grams of 1 mole of the substance. |
Empirical formula | The formula of a compound expressing the smallest whole number ratio of atoms in a compound. |
Molecular formula | The actual formula of a compound giving the types of atoms and numbers of each type of atom. |
Chemical reaction | One or more substances are changed into one or more new substances by the reorganization of component atoms. |
Chemical equation | A representation of a chemical reaction using the formulas of the starting substances that react and the new substances that are formed. |
Reactant | The starting substance of a chemical reaction, shown to the left of the reaction arrow. |
Product | The new substance formed by a chemical reaction, shown to the right of the reaction arrow. |
Coefficient | The number written in front of the chemical formulas in a balanced chemical equation. Coefficients indicate the relative numbers of reactants and products in the reaction. |
Precipitation | The formation of a solid in a chemical reaction. |
Precipitate | The solid that forms in a precipitation reaction. |
Precipitation reaction | A reaction in which a solid forms and separates from the solution. |
Strong electrolyte | A substance that dissolves in water by dissociating completely into ions. |
Soluble solid | A solid that readily dissolves in water. |
Insoluble solid | A solid that dissolves to such a small degree that it is not detectable to the naked eye. |
Molecular equation | A chemical equation showing the complete forms of all reactants and products. |
Complete ionic equation | A chemical equation for a reaction in solution representing all strong electrolytes as ions. |
Spectator equation | A chemical equation for a reaction in solution representing all strong electrolytes as ions. |
Net ionic equation | A chemical equation for a reaction in solution showing only those components that are directly involved in the reaction. Strong electrolytes are represented as ions. |
Strong acid | An acid that completely dissociates to produce H+ ions in solution. |
Strong base | A base that completely dissociates to produce OH- ion in solution. |
Salt | An ionic compound. |
Oxidation-reduction reaction | A chemical reaction involving the transfer of electrons. |
Combustion reaction | A chemical reaction involving oxygen as one of the reactants that produces enough heat so that a flame results. |
Decomposition reaction | A chemical reaction in which a compound is broken down into simpler compounds, or to the component elements. |
Synthesis reaction | A chemical reaction in which a compound is formed from simpler materials. |