Chemistry 10: Acids, Bases, and Atomic Theory

Acid

Starts with H (hydrogen). Tastes sour, turns blue litmus red. Examples: HCl, H2SO4

Base

Ends in OH (hydroxide) or has NH3 or NH4+. Tastes bitter, feels slippery, turns red litmus blue. Examples: NaOH, NH3

Salt

Usually made of a metal + non-metal (but no H at the front or OH at the end). Comes from an acid + base reaction. Examples: NaCl (from HCl+NaOH), KNO3, CaSO4

None (not acid, base, or salt)

Does not fit any of the above patterns. Examples: CH4 (methane), H2O (water), C6H12O6 (glucose)

Atom

The smallest particle of any element that retains the properties of the element.

Compound

A pure substance that is composed of two or more atoms combined in a specific way.

Proton (P)

+1 charge, located in the nucleus.

Electron (e)

-1 charge, surrounds the nucleus in shells.

Neutron (n)

0 charge, located in the nucleus.

Nuclear Charge

The electric charge on the nucleus, found by counting the number of protons. It is the same as the atomic number.

Atomic Number of a neutral atom

Equals the number of protons and the number of electrons.

Ion

An atom that has gained or lost at least one electron.

Cations

Metals generally lose electrons and have a positive charge.

Anions

Non-metals tend to gain electrons during a chemical reaction, which means they become negative ions.

Multivalent

Some metals can form more than one type of ion.

Bohr Diagrams

Diagrams that show the arrangement of an element's electrons in shells outside the nucleus.

Shells

Can hold a certain number of electrons. The first shell holds 2, the 2nd and 3rd shells hold a maximum of 8.

Stable Octet

When the outer shell contains 8 electrons, it is stable.

Valence Electrons

The electrons in the outermost shell.

Valence Shell

The outermost shell.

Chemical Bond

Forms when atoms interact and arrange their electrons to achieve a stable octet.

Ionic Bond

Formed between atoms that gain and lose electrons (a transfer of electrons). Usually between a metal and a non-metal.

Covalent Bond

Formed when two or more non-metals combine by sharing electrons.

Lone Pair

A pair of electrons not used in bonding in the valence shell.

Lewis Diagram (or Lewis Structure)

A diagram that illustrates chemical bonding by showing only an atom's valence electrons and the chemical symbol.

Diatomic molecule

A pair of identical atoms joined by covalent bonds. Example: H2 N2 O2 F2 Cl2 Br2 I2.

Ionic Compounds

Compounds composed of a metal (positive ion) and a non-metal (negative ion).

Naming Ionic Compounds

Name the metal first. Name the non-metal second, but change the ending to 'ide'.

Naming Compounds Containing a Multivalent Metal

If a chemical name contains a multivalent metal, a Roman numeral must be included in brackets to indicate the ion charge.

Polyatomic Ions

A polyatomic ion is a charged group of atoms that are joined by a covalent bond.

Naming compounds with polyatomic ion

Identify the two ions. If there is no ammonium, name the metal ion (including a Roman numeral if it is multivalent). Name the polyatomic ion.

Covalent Compounds

Made with non-metal elements.

Naming Covalent Compounds

Use prefixes to indicate the number of atoms of each element. Name the first element. Name the second element, changing the ending to 'ide'. Add a prefix to each name indicating the number of each. (Do not use 'mono' for the first element).

Law of Conservation of Mass

The number of each atom must be the same on both sides of the reaction arrow.

Reactants

The substances you start with.

Products

The substances you end with.

Acids

Produce H+ ions (hydrogen ions). pH < 7. Corrosive.

Bases

Produce OH− ions (hydroxide ions). pH > 7. Used in cleaning products.

pH Scale

Each whole number change in pH represents a factor of 10 change in acidity or basicity.

Indicators

Chemicals that change color depending on the pH.

Binary Acids

Hydrogen + non-metal. Prefix 'hydro-' is used at the beginning, and the non-metal name is replaced with the suffix '-ic'. The word 'acid' is added at the end. Ex. HCl is hydrochloric acid.

Complex Acids

Hydrogen + polyatomic ion. 'hydrogen' is dropped. If the polyatomic ion ends in '-ate', it is replaced with '-ic'. If it ends in '-ite', it is replaced with '-ous'. The word 'acid' is added.

Salts

A type of ionic compound that can be formed during the reaction of an acid and a base.

Neutralization Reaction

An acid and a base react to form a salt and water.

Oxide

A chemical compound that includes at least one oxygen atom or ion along with one or more other elements.

Metal Oxides

React with water to form basic solutions.

Non-metal Oxides

React with water to form acidic solutions.

Acids and Metals

Most metals react with an acid to form hydrogen gas and a salt.

Acids and Carbonates

If an acid is added to a compound containing carbonates (CO3), a salt, water, and carbon dioxide are produced.

Organic Compounds

Almost all compounds containing carbon.

Inorganic Compounds

Almost any compound without carbon.

Hydrocarbon

One kind of organic compound that contains only C and H.

Reaction Rate

How quickly or slowly reactants turn into products.

Factors that affect reaction rate

Temperature: Higher temperature = faster reaction. Concentration of reactants. Surface area: Increased surface area = faster reaction. Catalyst: A substance that speeds up a reaction without being used up itself. Inhibitor: A substance that slows down a reaction.

Wave

Something that moves through a medium.

Radiation

Transfer of energy from a source by waves.

Radioactivity

Release of high-energy particles and bursts of energy from a substance as a result of changes in the nucleus of its atoms.

Isotope

Different atoms of a particular element with the same number of protons but a different number of neutrons.

Alpha Radiation (α)

A stream of alpha particles. Positively charged. Blocked by paper.

Beta Radiation (β)

A stream of high-energy beta particles (electrons). Negatively charged. Blocked by aluminum foil.

Gamma Radiation (γ)

A stream of high-energy, short-wavelength electromagnetic radiation (gamma rays). Neutral. Requires blocks of lead or concrete to stop.