Atomic Structure and the Periodic Table

Atomic Structure

• Atoms are composed of protons, neutrons, and electrons.
• Protons carry a positive charge, electrons a negative charge, and neutrons are neutral.
• Protons and neutrons reside in the atom's nucleus, while electrons orbit the nucleus.

Atomic Number, Mass, and Isotopes

• Atomic number represents the number of protons in an atom.
• Atomic mass refers to the average mass of an atom, considering isotopes.
• Isotopes are atoms of the same element with different numbers of neutrons.

The Periodic Table

• The periodic table organizes elements based on their atomic number and properties.
• Elements are arranged in groups (vertical columns) and periods (horizontal rows).
• Groups share similar chemical properties due to a similar number of valence electrons.
• Periods show trends in atomic size and electronegativity.

Element Properties and Categories

• Elements are classified as metals, nonmetals, or metalloids based on their properties.
• Electronegativity measures an element's ability to attract electrons in a chemical bond.
• Atomic radius increases down a group and decreases across a period.

Chemical Bonding

• Ionic bonds form between a metal and a nonmetal through the transfer of electrons.
• Covalent bonds form between nonmetals through the sharing of electrons.
• Metallic bonds form between metal atoms by sharing a "sea" of delocalized electrons.

Predicting Bond Types

• Bond types can be predicted based on the types of elements involved in the reaction.

Chemical Equations

• Chemical equations represent chemical reactions.
• Chemical equations are balanced to maintain conservation of mass.

Types of Chemical Reactions

• Synthesis reactions combine two or more substances to form a more complex one.
• Decomposition reactions break down a complex substance to simpler ones.
• Other types of reactions exist, such as single-displacement/replacement, double-displacement/replacement, and combustion reactions.