Periodic Table: Periods, Groups, Metals & Non-metals

• The periodic table organizes elements into periods (rows) and groups (columns).

Periods vs. Groups

• Periods are horizontal rows that indicate the number of electron shells.
• Groups are vertical columns containing elements with similar chemical properties.
• Elements in the same group have the same number of valence electrons.

Names of Groups/Families

• Group 1: Alkali metals
• Group 2: Alkaline earth metals
• Group 17: Halogens
• Group 18: Noble gases

Metals vs. Non-metals vs. Metalloids

• Metals are typically lustrous, conductive, and malleable, located on the left side of the periodic table.
• Non-metals are generally dull, poor conductors, and brittle, found on the upper right side of the periodic table.
• Metalloids (semi-metals) have properties of both metals and non-metals, located along the staircase line.

Organization of the Periodic Table

• Elements are arranged by increasing atomic number.
• Elements with similar properties are placed in the same group.

Atoms vs. Ions

• Atoms are neutral species containing equal numbers of protons and electrons.
• Ions are charged species formed by the gain (anions) or loss (cations) of electrons.

Counting PEN for Atoms and Ions

• Protons determine the element's atomic number and identity.
• Electrons determine the ion's charge.
• Neutrons affect the mass number and determine the isotope.

Naming Ionic Compounds/Writing Chemical Formulas

• Ionic compounds consist of a metal and a non-metal or polyatomic ions.
• Molecular compounds consist of two or more non-metals.
• Acids usually start with hydrogen (H).
• Bases typically contain hydroxide (OH).

Multivalent Ions and Polyatomic Ions

• Multivalent ions (transition metals) can form multiple charges, indicated by Roman numerals in the name.
• Polyatomic ions are groups of atoms with an overall charge.

Properties of Ionic, Molecular Compounds, Acids vs. Bases

• Ionic compounds have high melting and boiling points and conduct electricity when dissolved in water.
• Molecular compounds have low melting and boiling points and do not conduct electricity well.
• Acids have a pH less than 7 and can neutralize bases.
• Bases have a pH greater than 7 and can neutralize acids.

Differentiation Among Substance Classes

• Ionic compounds are formed through ionic bonding.
• Molecular compounds are formed through covalent bonding.
• Acids produce H+ ions in water.
• Bases produce OH- ions in water.

Acids and Bases Based on Properties

• Acids taste sour and turn litmus paper red.
• Bases taste bitter and turn litmus paper blue.

Neutralization

• Neutralization is the reaction between an acid and a base, forming water and a salt.

Explore the periodic table's organization: periods (rows) indicate electron shells, while groups (columns) share chemical properties due to valence electrons. Learn about alkali metals, halogens, noble gases, and distinguish between metals, non-metals, and metalloids based on their properties and location.