Chemical species and formulae

• Element


  Substance with identical proton count, cannot be simplified. Contains one type of atom.
• Chemical species


  Any single atom, molecule, ion or molecular ion. The smallest part of a substance.
• Periodic Table


  Arrangement of elements by increasing proton number.
• Metal Elements


  Located on the left side of the Periodic Table. All solid at room temperature, except mercury (l).
• Non-Metal Elements


  Located on the right side of the Periodic Table.
• Compound


  Substance made of two or more different elements that have been chemically bonded.
• Atom


  Basic unit of an element, represented by its symbol. Metal elements are atoms.
• Simple molecule


  Two or more atoms bonded together by covalent bonds.Some non-metel elements and all non-metal compounds are molecules.
• Diatomic Molecule


  Molecule consisting of two identical atoms; e.g., O2. Exceptions to these are phosphorus (P4) and sulfur (S8)
• Subscript Number


  Indicates the number of atoms in a molecule.
• Cation


  Positively charged ion formed from metal elements. Form when metal atoms lose electrons.
• Anion


  Negatively charged ion formed from non-metal elements. Form when non-metal atoms gain electrons.
• Ionic Compound


  Formed from the combination of cations and anions. It's formula has no charge because the total charges of the negative and positive ions cancel out. Solid at room temperature.
• Hydroxide Ion


  Negative molecular ion with formula OH-.
• Ammonium Ion


  Positive molecular ion with formula NH4+.
• Nitrate Ion


  Negative molecular ion with formula NO3-.
• Carbonate Ion


  Negative molecular ion with formula CO3^2-.
• Sulfate Ion


  Negative molecular ion with formula SO4^2-.
• Phosphate ion


  Negative molecular ion with formula PO4^3-
• Molecular ions


  Charged chemical species that contain two or more elements.
• Ions


  Species with a positive or negative charge. Only found in compounds with other ions of the opposite charge.
• Roman Numerals


  Indicate the charge of metal ions in compounds.
• Ionic Formula

  Shows ratio of ions in an ionic compound.
• Balancing Charges


  Adjusting subscripts to achieve total charge of zero.
• State symbols


  Indicate physical state: (s), (l), (g), (aq).
• Molecular substances


  Formed between non-metal elements, can vary states.
• Aqueous solution


  Ionic compound dissolved in water, indicated by (aq).
• Effervescence


  Bubbles of gas produced in a solution.
• Precipitation


  Insoluble solid forms from a solution.
• Exothermic reaction


  Heat released, temperature increases during reaction.
• Endothermic reaction


  Heat absorbed, temperature decreases during reaction.
• Dissociation of acids


  Acids separate into ions in water, forming aqueous ionic solutions.
• Hydrochloric acid


  Chemical formula: HCl, produces H+ and Cl- ions.
• Sulfuric acid


  Chemical formula: H2SO4, produces H+ and SO4^2- ions.
• Nitric acid


  Chemical formula: HNO3, produces H+ and NO3- ions.
• Phosphoric acid


  Chemical formula: H3PO4, produces H+ and PO4^3- ions.
• Damp litmus paper


  Indicates pH: red for acids, blue for alkalis.
• Soluble substances


  Dissolve in solvents to form solutions.
• Insoluble substances


  Do not dissolve in solvents.
• Observations in reactions


  Record color, state, and reaction vigor.