General Chemistry 1 (FINALS)

An Atomic View of Matter

• The topic overview contains Inside the Atoms, Ions and Molecules, and Compounds: When Atoms Combine

Inside the Atoms

• Atomic number indicates the quantity of protons in an atom
• An atom possessing 6 protons characterizes “carbon”

Example Atomic Number

• The amount of protons in gold is 79
• Atomic mass represents the total count of protons and neutrons within an atom

Isotopes

• Isotopes have an identical number of protons, but varying counts of neutrons
• Elements maintain a consistent proton count, but may present differing amounts of neutrons

Molecules and Ions

• Molecules are particles encompassing a minimum of two electrically neutral atoms
• Certain elements exist in nature as molecules
• Ions constitute an atom or group of atoms carrying either a positive or negative charge

Types of Ions

• Cations are positive ions resulting from electron loss
• Anions are negative ions forming from electron gain

Chemical Formulas

• Molecular formulas provide the precise count of each element in a substance
• Empirical formulas display the elements present and their simplest ratio within a substance
• Structural formulas illustrate the chemical bonds in molecules

Compounds: When Atoms Combine

• For neutral ionic compounds, positive and negative charges must equalize to zero

Ionic Compounds

• For compounds of two elements, the cation name precedes the anion name
• The anion suffix should be "-ide" (e.g., sodium chloride)
• Metals forming multiple cations have their charge denoted by Roman numerals in parentheses

Molecular Compounds

• The first element is named and ends in "-ide"
• For nonmetal compounds, the less electronegative element is written first

Greek Prefixes for Compounds

• mono- = 1
• di- = 2
• tri- = 3
• tetra- = 4
• penta- = 5
• hexa- = 6
• hepta- = 7
• octa- = 8
• nona- = 9
• deca = 10
• The "a" at the end of prefixes attached to oxides is omitted (e.g., tetra oxide becomes tetroxide)
• "Mono" can be omitted from the first element if it only has one atom (e.g., monocarbon dioxide becomes carbon dioxide)

Stoichiometry

Avogadro’s Number & Mole Concept

• Avogadro's number is by Amadeo Avogadro and is a representative particle

• Number of representative particles = moles × 6.02 × 10^23

• Number of moles = representative particles / 6.02 × 10^23

Technique in Converting Moles

• Cancel one unit
• Introduce a new (desired) unit

Molar Mass

• It signifies the mass in grams within one mole of a substance, expressed in g/mol

Percent Composition and Chemical Formulas

• % mass of element = (mass of element / mass of compound) × 100%

Chemical Reactions And Equations

• Chemical equations symbolize chemical processes, showing reactants converting into products

Chemical Equation Symbols:

• → Yields, gives, reacts to produce
• ←→ Reversible reaction
• ↓ A precipitate formed

Types of Chemical Reactions

• Combustion: substances react with oxygen, releasing heat and light
• Combination/Synthesis: two or more substances combine into a single new substance
• Decomposition: a compound breaks down into two or more simpler substances
• Single Replacement/Displacement: one element replaces another in a compound
• Double Replacement/Displacement: exchange of positive ions between two compounds

Gas laws

• The gas laws include Boyle’s law, Charle’s law, Avogadro’s law and Gay-Lussac’s law.

Boyle’s Law

• A gas has an initial volume of 3.0 L at 2.0 atm.
• If the pressure is increased to 6.0 atm, what is the new volume?​
• The solution is 1.0 L.

Electronic Structure of Atoms

• Thomson’s Pudding Model: Electrons are in a positive cloud
• Rutherford’s Nuclear Model: Positive charge and mass is concentrated in the nucleus
• Neils Bohr Atomic Model: Electrons move in orbits around the nucleus.

Quantum Numbers to Describe Orbitals

• n or The principal quantum number, describes energy of the electron
• The angular momentum quantum number (azimuthal), describes the shape of the electron.
• when l = 0; electron is in the s sublevel
• when l = 1; electron is in the p sublevel
• when l = 2; electron is in the d sublevel
• when l = 3; electron is in the f sublevel
• The magnetic quantum number describes electron orientation
• When l = 0, ml has 0 value
• When l =1, ml has 3 values
• When l= 2, ml has 5 values
• When l = 3, ml has 7 values
• Spin quantum number (mₛ)describes the spin of the electron, clockwise and counterclockwise

Writing the Electron Configuration of Atoms

• Electrons are distributed in an atom’s representation
• To distribute the atom, start from the orbital with lowest energy to distribute the electrons
• Numbers and letters are used and represent the principal energy levels and the sublevel (orbital) respectively

Aufbau Building Principle

• Electrons fill orbitals in increasing energy order
• 1s is the lowest energy orbital
• Above the 3p level, overlaps of sublevel occur

Orbital Diagrams

• • Boxes containing arrows representing oribitals

Chemical Bonding

• Chemical bonding is the attraction between atoms, ions, and molecules to form a compound

Types of Chemical Bonds

• • Metalic Bonds, Ionic Bonds, Covalent Bonds

Rules For Writting Electron Configurations

• Distribute atoms starting from the lowest to highest energy levels
• Numbers and letters are used to show primciple energy levels and sublevels

Metals and Nonmetals

• Group 1 (Li, Na, K, Rb, Cs, Fr) lose 1e-
• Group 7 (F, Cl, Br, I, At) gain de-
• Group 2 (Be, Mg, Ca, Si, Ba, Ra) metals, lose 2e-
• Group 6 (O, S, Se, Te, Po) nonmetals, gain 2e-

Covalent Bonds

• Mutual sharing of electron between two non-metals
• Single Covalent Bond - 2 atoms share 1 pair of e-
• Double Covalent Bond - 2 atoms share 2 pairs of e-
• Triple Covalent Bond - 2 atoms share 3 pairs of e-

Organic Compounds

• Organic chemistry deals with Carbon
• Organic compounds entail carbon and oxygen or carbon and hydrogen with oxygen, nitrogen, and sulfur.
• Carbon can establish strong covalent bonds forming into chains and rings
• A hydrocarbon is a simple organic compound, consistuting carbon and hydrogen
• Methane (CH4) is the basic organic compound

Alkanes

• Carlanes are single open chain band, and are saturated with hydrogen
• Alkane - formula

Cyclic/Closed chain Hydrocarbons

• Cycloalkane are single bonded carbon atoms
• Formula of cyclo can =