Term | Definition |
ion | an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. |
isotope | each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element |
valence electron | an electron that is associated with an atom, and that can participate in the formation of a chemical bond |
ionic bonds | the electrostatic bond between two ions formed through the transfer of one or more electrons. |
covalent bonds | the bond formed by the sharing of a pair of electrons by two atoms. |
diatomic elements | The elements ending with "-gen" including halogens form diatomic molecules. Hydrogen (H2)
Nitrogen (N2)
Oxygen (O2)
Fluorine (F2)
Chlorine (Cl2)
Iodine (I2)
Bromine (Br2) |
molecular compound | A compound with covalent bonds. Same as a covalent compound. |
polar bond | A polar bond is a covalent bond between two nonmetal atoms where the electrons forming the bond are unequally distributed. Therefore, one part of molecule is positive and the other negative. Ex. water |
nonpolar bonds | A nonpolar bond is a covalent bond between two nonmetal atoms where the electrons forming the bond are equally distributed. Therefore, the molecule has a zero charge. |
organic compounds | Compounds that contain carbon. |
inorganic compounds | Compounds without carbon. |
chemical formula | The way of expressing the atoms in a compound. |
chemical
equation | The way of expressing the chemical reaction of two or more compounds. |
reactants | a substance that takes part in and undergoes change during a reaction. |
products | a substance obtained from another substance through chemical change. |
coefficients | a number that is constant for a given substance, body, or process under certain specified conditions, serving as a measure of one of its properties: |
exothermic reaction | Exothermic reactions give off heat (product). It gives off heat to its surrounding (the water). The extra heat makes the solution hotter and so temperature goes UP. |
endothermic
reaction | Endothermic reactions require heat to proceed. The heat that they use up comes from the solution. Since heat is being used up, the temperature drops. |
acid | a chemical substance that neutralizes alkalis, dissolves some metals, and turns litmus red; typically, a corrosive or sour-tasting liquid of this kind. |
base | a compound that reacts with an acid to form a salt, as ammonia, calcium hydroxide, or certain nitrogen-containing organic compounds. |
pH scale | measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. |