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Chapter 4 Vocab
Term | Definition |
---|---|
Element | A substance that cannot be separated or broken down into simpler substances by chemical means. |
Pure Substance | A sample of matter either a single element or a single compound that has definite chemical and physical properties. |
Metal | An element that is shiny and that conducts heat and electricity. |
Nonmetal | An element that conducts heat and electricity poorly. |
Metalloid | An element that has properties of both metals and nonmetals. |
Compound | A substance made up of atoms of two or more different elements joined by chemical bonds. |
Mixture | A combination of two or more substances that are not chemically combined. |
Solution | A homogeneous mixture of two or more substances uniformly dispersed throughout a single phase. |
Solute | In a solution, the substance in which the solute disolves. |
Solvent | In a solution, the substance in which the solute disolves. |
Concentration | The amount of a particular substance in a give quantity of a mixture, solution. |
Solubility | The ability of one substance to dissolve in another at a given temperature and pressure. |
Suspension | A mixture in which particles of a material are more or less evenly dispersed throughout a liquid or gas. |
Colloid | A mixture consisting of tiny particles that are intermediate in size between those in solutions and those in suspensions and that are suspended In a liquid. |
Centrifuge | Machine that separates mixtures by the densities of their components. |
Distillation | Process that separates mixtures based on the boiling points of the components. |
Atom | The smallest unit of an element that maintains the properties of that element. |
Electron | A subatomic particle that has a negative charge |
Nucleus | In physical science---an atom's central region, which is made of neutrons and protons. |
Electron cloud | A region around the nucleus of an atom where electrons are likely to be found. |
Proton | A subatomic particle that has a positive charge and that is found in the nucleus of an atom. |
Atomic mass unit | A unit of mass that describes the mass of an atom or molecule. |
Neutron | A subatomic particle that has no charge and that is foundin the nucleus of an atom. |
Atomic number | The number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element. |
Isotope | An atom that has the same number of protons (or the same atomic number) as other atoms of the same element do, but that has a different number of neutrons (and thus a different atomic mass). |
Mass number | The sum of the numbers of protons and neutrons in the nucleus of an atom. |
Atomic mass | The mass of an atom expressed in atomic mass units. |
Alkali Metals | One of the elements of group 1 of the periodic table (Lithium, Sodium, potassium, etc.) |
Alkaline Earth Metals | One of the elements of group 2 of the periodic table (Beryllium, Magnesium, calcium, etc.) |
Group | A vertical column of elements in the periodic table; elements Ina group share chemical properties. |
Halogen | One of the elements of group 17 of the periodic table (Flourine, Chlorine, Bromine, iodine, etc.); halogens combine with most metals to form salts. |
Period | In chemistry, a horizontal row of elements in the periodic table. |
Periodic | Describes something that occurs or repeats at regular intervals. |
Periodic Law | The law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements. |
Noble Gas | One of the elements of group 18 of the periodic table (helium, neon, argon, etc.); noble gases are unreactive. |