The Periodic Table

Periodic Table

• The periodic table is a tabular display of the known chemical elements, organized by their atomic number (number of protons in the nucleus), electron configuration, and recurring chemical properties.
• The elements are listed in order of increasing atomic number (number of protons in the nucleus) and are grouped into rows called periods and columns called groups or families.
• The periodic table is divided into different sections:
  • Metals (left side and center of the periodic table)
  • Nonmetals (right side of the periodic table)
  • Metalloids (border between metals and nonmetals)
• The periodic table allows us to:
  • Identify relationships between elements
  • Predict chemical properties and behaviors
  • Identify trends and patterns in element properties

Chemical Reactions

Types of Chemical Reactions

• Synthesis reactions: two or more substances combine to form a new compound
• Decomposition reactions: a single compound breaks down into two or more substances
• Single displacement reactions: one element displaces another element from a compound
• Neutralization reactions: an acid reacts with a base to form a salt and water

Chemical Reaction Basics

• Chemical equations: representations of chemical reactions using chemical formulas and symbols
  • Reactants: substances on the left side of the equation
  • Products: substances on the right side of the equation
• Stoichiometry: the study of the quantitative relationships between reactants and products in chemical reactions
  • Moles: units of measurement for the amount of a substance
  • Molar ratios: ratios of moles of reactants to moles of products

Factors Affecting Chemical Reactions

• Concentration: the amount of a substance per unit volume
• Temperature: an increase in temperature generally increases the rate of reaction
• Surface area: an increase in surface area generally increases the rate of reaction
• Catalysts: substances that speed up chemical reactions without being consumed or altered

Periodic Table

• The periodic table displays chemical elements organized by atomic number, electron configuration, and recurring chemical properties.
• Elements are listed in order of increasing atomic number and grouped into periods (rows) and groups or families (columns).
• The table is divided into metals (left side and center), nonmetals (right side), and metalloids (border between metals and nonmetals).
• The periodic table allows for:
  • Identifying relationships between elements
  • Predicting chemical properties and behaviors
  • Identifying trends and patterns in element properties

Chemical Reactions

Types of Chemical Reactions

• Synthesis reactions: combine two or more substances to form a new compound
• Decomposition reactions: break down a single compound into two or more substances
• Single displacement reactions: one element displaces another element from a compound
• Neutralization reactions: acid reacts with a base to form a salt and water

Chemical Reaction Basics

• Chemical equations represent reactions using chemical formulas and symbols
  • Reactants: substances on the left side of the equation
  • Products: substances on the right side of the equation
• Stoichiometry studies quantitative relationships between reactants and products
  • Moles: units of measurement for the amount of a substance
  • Molar ratios: ratios of moles of reactants to moles of products

Factors Affecting Chemical Reactions

• Concentration: amount of a substance per unit volume affects reaction rate
• Temperature: increasing temperature generally increases reaction rate
• Surface area: increasing surface area generally increases reaction rate
• Catalysts: substances that speed up reactions without being consumed or altered