Introduction to Chemistry and Matter

• Chemistry is the study of substances, including their composition, behavior, and uses.
• A property is a feature or characteristic that describes a substance.
• Matter is anything that possesses mass and occupies space (volume).

Particle Theory of Matter

• All matter consists of tiny particles with empty spaces between them.
• Different substances are composed of different kinds of particles.
• Particles are in constant, random motion.
• The speed of particles increases with temperature.
• Particles are subject to attractive forces.

Substances and Mixtures

• Pure substances are made up of only one kind of material.
• Mixtures are made up of more than one pure substance.
• Pure substances can combine to form mixtures.

Physical Properties

• Physical properties are characteristics of a substance that can be determined without changing its composition.
• Physical properties can be detected using the five senses or measuring instruments.
• Examples include color, odor, taste, texture, luster, optical clarity, brittleness, viscosity, hardness, malleability, ductility, and electrical conductivity.

Qualitative vs. Quantitative Properties

• Qualitative properties do not provide numerical information (e.g., a wooden block is blue).
• Quantitative properties provide numerical information (e.g., the mass of the block is 14.5 g).

Chemical Properties

• Chemical properties are characteristic behaviors of a substance that are determined when the substance undergoes a change in composition, resulting in the production of one or more new substances.
• Examples include combustibility, reaction with acids, flammability, and resistance to corrosion.

Physical vs. Chemical Changes

• Physical changes do not alter the composition of the substance involved.
• Chemical changes involve the formation of one or more new substances.

Evidence of a Chemical Change

• Fizzing and bubbling (excluding boiling)
• Odor change
• Color change
• Temperature change (heat or light released)
• Formation of a new substance
• Chemical changes are hard to reverse

Elements

• All known elements are located on the Periodic Table.
• Elements are organized into 7 rows called periods.
• Elements are organized into 18 columns called groups or families.
• Elements are classified as metals, non-metals, or metalloids.
• Metals are silver, shiny, and solid.
• Non-metals are gases or liquids.
• Metalloids exhibit properties of both metals and non-metals.

Ions and Ionic Compounds

• An ion is a charged particle formed when an atom gains or loses one or more electrons.
• Ionic charge refers to the sum of positive and negative charges in an ion.
• An ionic compound is a compound formed when positive cations and negative anions join together.

Naming Ionic Formulas

• Write the full name of the metal as it appears on the Periodic Table.
• Write the name of the non-metal, changing the ending of its name to "ide" (e.g., BeO is Beryllium oxide).

Writing Ionic Formulas

• Write the chemical symbol for each element, with the metal listed first.
• Write the ionic charges above each symbol, based on the number of electrons gained or lost.
• Determine ionic charges from the Periodic Table.
• Criss-cross the numbers (charges), using them as subscripts (*omit + or - signs and any subscript for a charge of 1).
• Reduce the subscripts to the lowest common denominator, if necessary.
• A polyatomic ion is an ion formed by a group of atoms that share a charge.

Transition Metal Charges

• Chromium (Cr): 2+, 3+
• Iron (Fe): 2+, 3+
• Cobalt (Co): 2+, 3+
• Nickel (Ni): 2+, 3+
• Copper (Cu): 1+, 2+
• Zinc (Zn): 2+
• Silver (Ag): 1+
• Tin (Sn): 2+, 4+
• Gold (Au): 1+, 3+
• Mercury (Hg): 1+, 2+
• Lead (Pb): 2+, 4+

Molecular Compounds

• Molecules are groups of two or more non-metal atoms joined together.
• Molecular compounds are pure substances composed of non-metal elements joined together.
• The chemical formula of a molecular compound indicates the exact number of atoms of each element in the compound, with no reduction of ratios.
• Naming Molecular Compounds requires writing the names of both elements in the order they appear in the formula and changing the ending of the second element to "ide".
• Add prefixes to indicate the number of each type of atom (*mono is not used for the first element if there is only one of it).
• Writing Molecular Formulas requires writing the symbol of each element in the order given, then using the prefixes in the name to determine the number of atoms and writing that number as a subscript.
• Ionic compounds are stable metal to nonmetal and transfer electrons.
• Covalent compounds are nonmetal to nonmetal with sharing of electrons; no ions are formed.

Law of Conservation of Mass

• The total mass of the reactants must equal the total mass of the products.
• Atoms are neither destroyed nor created in a reaction.

Chemical Reactions

• There are five main types of chemical reactions.

Synthesis Reaction

• Atoms or molecules combine to make larger molecules.

Decomposition Reactions

• One larger compound splits into smaller atoms or molecules.

Single Displacement Reactions

• One atom displaces another atom in a compound (a metal displacing a metal; a nonmetal displacing a nonmetal).

Double Displacement Reactions

• Two atoms in different compounds displace each other (switching places).

Neutralization Reactions

• Acida nd bases react to produce salt and water.

Combustion Reactions

• A fuel (hydrocarbon comprised of hydrogen & carbon) burns with oxygen and releases energy as heat and light
• When COMPLETE combustion occurs, the products are always carbon dioxide and water.
• INCOMPLETE combustion produces a water, carbon dioxide (CO2), carbon monoxide (CO) and soot.

Acid and Base Nomenclature

• Acids are molecular compounds with similar chemical properties when dissolved in water.

Acids

• acids taste sour.
• acids have no texture (wet).
• Acids corrode.
• Acids react with metals,
• Acids contain ions that conduct electricity.
• acids turn litmus paper from blue to red

Binary Acids

• Binary acids contain hydrogen and a nonmetal (e.g. HCl).

Oxoacids/Oxyacids

• Oxoacids/Oxyacids contain hydrogen, a nonmetal, and oxygen (e.g., H3PO4).

Bases

• Bases are ionic compounds that taste bitter.
• Bases have a slippery texture.
• Bases may corrode.
• Bases do NOT react with metals.
• Bases contains ions that do not conduct electricity.
• bases turn litmus paper from red to blue.

Hydroxide Bases

• Hydroxide Bases are comprised of a cation and a hydroxide (OH-) ion (e.g. NaOH(aq)).

Carbonate Bases

• Carbonate Bases are comprised of a cation and a carbonate (CO32-) or bicarbonate (HCO3-) (e.g. MgCo3(aq)).
• The pH scale (power of hydrogen) is a scale ranging from 0-14 that allows you to determine if an acid or base is strong or weak.
• pH measures the concentration of H+.
• Red litmus paper turns red in acid and blue in base.
• Blue litmus paper turns red in acid and blue in base.
• Phenolphthalein is clear in acid and pink (magenta) in base.
• Bromothymol blue (BTB) is yellow in acid and blue in base.