CSET Multiple Subjects Subtest 2: Science; Mathematics 100% Pass

CSET Multiple Subjects Subtest 2: Science; Mathematics 100% Pass atom the smallest unit of an element that still holds the properties of the element. Made up of protons, neutrons, and electrons proton positively charged, located in the nucleus of the atom, has a mass of 1AMU neutron neutral charge, located in the nucleus of the atom, has a mass of 1 AMU electron has a negative charge, orbits outside of the nucleus, has a mass of 1/1836 AMU balanced atom same number of protons and electrons ion atom with an unbalanced charge--either positive or negative. isotope an atom with a different number of neutrons than the standard amount for that element. atomic mass the amount of matter that makes up an atom. Estimate in AMUs by adding up the protons and neutrons. atomic number The number of protons an atom has. This defines the type of element. half-life the time it takes for half of the atoms of a particular substance to disintegrate. carbon dating Method of measuring the ratio of Carbon 14 to Carbon 12. The longer something has been dead, the "more" carbon 12 it has. Only accurate on items <50,000 years old. periodic table of elements Elements are arranged in rows according to their atomic number, and columns loosely according to their chemical properties. compound a substance of 2 or more elements (ex. H20--water, CO2--carbon dioxide, NaCL--table salt) ionic bond bonds a metal with a non-metal. One atom loses an electron to form a positive ion, and the other gains an electron to form a negative ion; creating an electrostatic force that holds them together. covalent bond a bond formed when atoms share 1 or more of their valence electrons. chemical change the chemical composition of a substance is altered. hint: fire is an example of a chemical change taking place. catalyst something that starts a chemical change (ex. a spark) mixture material that can be separated by physical means into two or more substances solution homogenus mixture in which one substance is completely dissolved into another substance (ex. salt water) suspension a mixture in which small particles are kept dispersed by agitation or molecular motion in a surrounding medium (ex. muddy river water) physical change a change from one state to another without a change in the chemical composition of a substance