Elements, Compounds, and Mixtures

• Elements, compounds, and mixtures are distinct types of matter with unique properties.

Elements

• Elements are the simplest form of matter, possessing unique physical and chemical characteristics.
• An element consists of only one kind of atom.
• Elements cannot be broken down into simpler substances through physical or chemical methods.
• Examples of elements include silicon (Si), oxygen (O2), and copper (Cu).

Compounds

• Compounds consist of two or more different elements chemically bonded together.
• The elements in a compound are not simply mixed but have their atoms joined in a chemical reaction.
• Compounds can be broken down into simpler substances, which are their component elements.
• Examples of compounds include carbon dioxide (CO2), water (H2O), and ammonia (NH3).

Mixtures

• Mixtures are combinations of two or more substances (elements or compounds) physically intermingled.
• The components of a mixture do not chemically combine.
• The composition of a mixture can vary in terms of the mass of each component.
• A mixture of the compounds sodium chloride and Water is a mixture.

Isotopes

• Isotopes are atoms of the same element.
• Isotopes have the same atomic number.
• Isotopes have a varying number of neutrons.
• Isotopes have different mass numbers.

Atomic Mass

• Atomic mass is calculated by summing the product of each isotope's mass and its fractional abundance.
• The formula for calculating atomic mass is Σ (isotopic mass × fractional abundance) / 100.

Organization of the Periodic Table

• The periodic table organizes elements based on their properties.
• Metals are generally found on the large lower left portion of the periodic table.
• Metals are typically shiny solids at room temperature, with mercury being the only liquid metal.
• Metals conduct heat and electricity well and can be formed into sheets (malleable) and wires (ductile).
• Nonmetals are located on the smaller upper right portion of the periodic table.
• Nonmetals are generally gases or dull, brittle solids at room temperature, with bromine as the only liquid nonmetal
• Nonmetals are poor conductors of heat and electricity.
• Metalloids, or semimetals, are found in the green portion of the periodic table.

Key Groups in the Periodic Table

• Alkali metals are in Group 1A.
• Alkaline earth metals are Group 2A.
• Halogens are in Group 7A.
• Noble gases are in Group 8A.

Ions

• Metals lose electrons to form positive ions.
• Nonmetals gain electrons to form negative ions.

Compounds: Introduction to Bonding

• Ionic compounds result from the loss and gain of electrons between metals and nonmetals.
• Metals lose electrons to form cations.
• Nonmetals gain electrons to from anion
• Covalent compounds result from sharing electrons between nonmetal atoms.

Naming Ionic Compounds

• Refer to the official document for the complete set of rules for naming chemical compounds

Naming Ionic Compounds with Transition Metals

• Transition metals can have multiple valencies.
• Include the name of the transition metal, its valency, and the name of the nonmetal.

Naming Covalent Compounds

• Use prefixes such as mono, di, tri, etc.
• Add "ide" to the end of the compound