Bohr Rutherford Diagrams
• Nucleus contains number of protons and neutrons |
Energy levels:
• 1st energy level can have a maximum number of 2 electrons
• 2nd and 3rd can have a maximum number of 8 electrons |
Acids and Bases
Acid → A molecular compound that when dissolved in solution release H+ ions, called hydrogen ions. Most of the time, the hydrogen ion reacts with water to produce H3O+, also known as hydronium. |
Base → An ionic compound that when dissolved in solution will release OH- ions, called hydroxide ions. |
Atoms and Ions
Atom: An electrically neutral particle with an equal number of protons and electrons. |
Ion: A charged particle that results when an atom gains or loses one or more electrons. |
Atoms tend to gain, lose, or share electrons so that the valence shell has 8 electrons. Ionic compounds are stable when the outermost shell is full. when an atom transfers electrons to another atom, ions are created. |
Balancing Chemical Equations
Step 1: Count number of atoms of each element |
Step 2: Pick and element that doesn’t have equal number of atoms on each side (usually do H and O at the end) |
Step 3: Add coefficients in front of formula unit/molecule with that element and adjust counts |
Step 4: Continue adding coefficients until there is the same number of atoms on each side. |
Chemical Formula of Ionic Compounds
Step 1: Write symbols → metal first, non-metal second. |
Step 2: Write ionic charge above each symbol. |
Step 3: Criss cross the numbers → they become the subscript on the opposite element symbol. |
Step 4: Write formula and reduce to the lowest terms. |
Chemical Formulas for Compound w/ Polyatomic Ions
Step 1: Write symbols, metal first, polyatomic ion second. |
Step 2: Write ionic charge next to each symbol. |
Step 3: Criss-cross the numbers, using them as subscripts. |
Step 4: Write the formula and reduce to lowest terms. |
Cation vs. Anion
Cations (Metals): Tend to lose electrons, positive charge
Elements in groups 1, 2, & 13 form cations. |
Anions (Non-Metals): Tend to gain electrons, negative charge
Elements in groups 15,16, & 17 form anions. |
|
|
POLYATOMIC IONS
Hydroxide → |
OH- |
Nitrate → |
NO3- |
Carbonate → |
CO32- |
Chlorate → |
ClO3- |
Hydrogen Carbonate → |
HCO3- |
Sulfate → |
SO42- |
Phosphate → |
PO43- |
Ammonium → |
NH4+ |
Evidences of a Chemical Reaction
→ Formation of a gas |
→ Formation of a precipitate (solid) |
→ Change in colour |
→ Change in energy. |
Naming Bases
Bases- Contain hydroxide ions and a metal. |
Step 1: Add the name of the metal. |
Step 2: Add hydroxide. |
Types of Chemical Reactions
Synthesis: Two reactants combine to make a larger product. A + B → AB |
Decomposition: A large reactant breaks down to form two or more simpler products. AB → A + B |
Single Displacement: An element displaces another element in a compound, producing a new compound and a new product.
AB + CD → CB + AD |
Double Displacement: Elements in different compounds displace each other, producing two new compounds. AB + CB → AD + CB |
The Law of Conservation of Mass
The Law of Conservation of Mass states that in any chemical reaction, the total mass of the reactants is equal to the total mass of the products. (Atoms can’t be created or
destroyed.) |
Tricky Metals`
Some metals can form more than one kind of ion. For example, copper can have an ionic charge of 1 or 2 depending on the reaction. |
CuCl is called
Copper (I) Chloride |
CuCl2 is called
Copper (II) Chloride |
The Periodic Table
• Groups are the number of valence electrons (1-8), and periods represent the number of orbits (1-7). |
• Atomic number: Number of protons and electrons. |
• Atomic mass: Relative mass of the atom. |
• Neutrons = Atomic number - atomic mass. |
|
|
Naming Compounds With Tricky Metals
Step 1: Move each subscript to the opposite element |
Step 2: Change subscript values to an ionic charge |
Step 3: Check to see if the non-metals ionic charge is correct |
Step 4: If step 3 is incorrect, multiply both ionic charges to equal the correct value |
Molecules and Covalent Bonding
Molecular (covalent) compound: A pure substance formed between two or more
non-metals. |
Covalent bond: Bond that forms from the sharing of outer electrons between non-metal atoms. |
Diatomic molecule: Molecule consisting of two atoms joined by a covalent bond. Halogens can form diatomic molecules. |
Writing Chemical Formulas for Molecular Compounds
Prefixes in names become subsripts in the formula. |
Nitrogen monoxide → |
NO |
Sulfur dioxide → |
SO2 |
Arsenic tribromide → |
AsBr3 |
Ionic Compounds
Ionic Compound → Bond that forms between a positive ion (cation) and a negative ion (anion). |
Ionic compounds form whenever an electron is transferred from a metal to a non-metal. The oppositely charged ions attract eachother. |
Lewis diagram: Symbol with valence electrons
Neutralization Reaction
Acid + Base → Salt + Water |
Neutralization reaction: A reaction between an acid and base to form an ionic compound (salt) and water. |
aq stands for aqueous solution. |
Naming Acids
Binary acids → Contain only two elements; hydrogen, and a non-metal. |
Step 1: Use hydro as a prefix |
Step 2: Add the stem name of the non-metal |
Step 3: Change the ending of the non-metal to ic |
Step 4: Add ‘acid’ |
Oxyacids → contain three or more elements; hydrogen, oxygen, and a non-metal. |
Step 1: Polyatomic ending “ate” dropped |
Step 2: Ending “ic acid” is added. |
Groups
1. Alkali Metals - One valence electrons, highly reactive (especially with water), soft, reactivity decreases moving up. |
2.Alkaline Earth Metals - Two valence electrons, reactive, mineral nutrients. |
3-12. Transition Metals - Hard, multiple ionic charges |
17. Halogens - Seven valence electrons, reactive non-metals. |
18. Noble Gases - Full valence shell, stable. |
|
