Chemistry Chapter on Atomic Structure and Periodic Table

Atomic Structure and Properties

• Atoms are composed of protons, neutrons, and electrons
• The nucleus, containing protons and neutrons, is dense and positively charged
• Electrons orbit the nucleus and are negatively charged
• Protons and neutrons are heavy subatomic particles
• Electrons are light subatomic particles

Atomic Number and Mass Number

• Atomic number defines an element and equals the number of protons.
• Mass number is the total number of protons and neutrons in an atom
• Calculate neutrons: Mass number - Atomic number = number of neutrons

The Periodic Table

• Elements are organized by their properties.
• Arrangement: Red, blue, black, and clear colors are used to categorize elements as liquids, gases, solids, or synthetic, respectively on the periodic table.
• Periods: Horizontal rows on the periodic table
• Groups: Vertical columns on the periodic table
• Metal properties: Shiny, malleable, ductile, conductive, sometimes magnetic
• Nonmetal properties: Dull, brittle, poor conductors
• Metalloid properties: Properties of both metals and nonmetals

Isotopes

• Isotopes are atoms of the same element with different neutron numbers, meaning different mass numbers.
• Isotopes have the same number of protons but different numbers of neutrons.

Chemical Formulas

• Two types of chemical formulas exist: empirical and molecular formulas.

Atomic Mass

• The average mass of an element's atoms, considering the relative abundance of its isotopes

Combustion Analysis

• Determining the elemental composition of a substance by combustion to find the empirical formula

Ions

• Ions are atoms that have gained or lost electrons, giving them a positive or negative charge.
• Cations are positively charged ions
• Anions are negatively charged ions

Types of Bonds

• Covalent bonds: atoms share electrons
• Ionic bonds: atoms transfer electrons

Molecular Compounds & Properties

• Formed from two or more nonmetals
• Properties: weak bonds (low melting and boiling points), poor heat and electrical conductivity, and typically exist as solids, liquids, or gases at room temperature.

Ionic Compounds & Properties

• Formed from a metal and a nonmetal
• Properties: high melting and boiling points, hard and brittle, conduct electricity when melted or dissolved in water, and generally occur as solids at room temperature.

Chemical Nomenclature

• Rules for naming chemical compounds, including compounds with variable charges (indicated using Roman numerals)

Atomic Elements

• Elements existing as single atoms

Molecular Elements

• Elements existing as two or more atoms bonded together (molecules)

Monoatomic Anions

• Anions composed of one atom

Periodic Table Elements

• Specific elements listed by name and formula including: Fluorine (F-), Chloride (Cl-), Bromide (Br-), Iodine (I-), Oxide (O2-), Sulfide (S2-), Nitride (N3-), Phosphide (P3-).

Identifying and Calculating Molarity, Solutions, Solvents & Solutes.

• Molarity: amount of solute per liter of solution
• Solution: a homogeneous mixture of two or more substances.
• Solvent: the substance in which the solute dissolves.
• Solute: the substance that dissolves in the solvent

Formula for Dilution Problems

• M1V1=M2V2