Chemistry Chapter 2-5 Test
compound
a chemical combination of two or more different elements joined together in a fixed proportion
molecule
aggregate (group) of two or more atoms in a definite arrangement held together by chemical bonds
ion
an atom, or group of atoms, that has a net positive or negative charge
octet rule
atoms will gain, lose, or share elections in order to fill their outer energy level
transition metals
can have more than one type of charge, so we use Roman numerals to indicate what the charge is
ternary compound
compound containing more than two elements
binary compound
compound containing two elements
ionic compound
compound made of ions
molecular (covalent) compounds
compounds that form molecules
acids
compounds that from H+ in water
hydrates
compounds that have a specific number of water molecules attached to them
polyatomic ion
contains more than one atom
polyatomic molecule
contains more than two atoms (O3, H2O, NH3)
monatomic ion
contains only one atom
diatomic molecule
contains only two atoms (H2, N2, HCl, CO)
properties of ionic compounds
crystal lattice structure, conducts electricity when dissolved or melted (electrolytes), high melting and boiling points, solids at room temperature, hard and brittle, rarely burn
valence electrons
electrons located in the outermost energy levels of an atom
properties of molecular (covalent) compounds
form molecules, low melting and boiling point, solids, liquids, or gases at room temperature, don't dissolve as well in water as ionic compounds, don't conduct electricity, sometimes burn
anion
ion with a negative charge (gains electron(s))
cation
ion with a positive charge (loses electron(s))
molecular formula
shows the exact number of atoms of each element in the smallest unit of a substance
empirical formula
shows the simplest whole-number ratio of the atoms in a substance
atomic number
tells you the number of protons in an element (top number)