Chemistry Class: Periodic Table & Chemical Reactions

Periodic Table Structure and Element Classification

• Periods: Horizontal rows on the periodic table; indicate the number of electron shells an element has.
• Groups: Vertical columns; elements share similar chemical properties due to the same number of valence electrons.
• Metals: Lustrous, good conductors of heat and electricity, malleable, and ductile (e.g., Iron, Copper).
• Nonmetals: Dull, poor conductors, brittle (e.g., Carbon, Sulfur).
• Noble Gases: Inert, full valence electron shells, low reactivity (e.g., Helium, Neon).
• Arrangement: Elements arranged by increasing atomic number.
• Categories: Elements categorized as metals, nonmetals, and metalloids.
• Key Trends: Atomic size, ionization energy, and electronegativity are key trends across the periodic table.

Acids, Alkalis, and Balancing Chemical Equations

• Acids: Substances with a pH less than 7, sour taste, and turn blue litmus paper red (e.g., HCl, H₂SO₄).
• Alkalis (Bases): Substances with a pH greater than 7, slippery feel, and turn red litmus paper blue (e.g., NaOH, KOH).
• Neutralization Reaction: Acid + Alkali → Salt + Water.
• Indicators: Substances that change color to indicate acidity or alkalinity.
• Common Indicators: Litmus paper, Phenolphthalein, and Methyl orange are examples.
• Industrial and Other Uses: Acids have applications in industrial processes, cleaning agents, and food preservation.

pH Measurement and Experimental Protocols

• pH Scale: Ranges from 0 to 14; measures hydrogen ion concentration.
• pH Meters: Used to measure pH accurately.
• Experiment Protocols: Proper use of pH meters, solutions preparation, and safety precautions are essential.
• Universal Indicator: Shows pH on a scale.
• Natural Indicators: Plant extracts (e.g., red cabbage juice) can be used as indicators.

Displacement Reactions

• Displacement Reaction: A more reactive element displaces a less reactive one from its compound.
• Example: Zn + CuSO₄ → ZnSO₄ + Cu (Zinc displaces Copper.)
• Applications: Used in metal extraction and galvanization.

Upcoming Topics

• Advanced Chemical Reactions: More complex chemical reactions will be covered.
• Experiment-Based Learning: Experiments on pH and reactivity will be conducted.

This quiz covers key concepts related to the periodic table, including element classification into metals, nonmetals, and noble gases. It also explores fundamentals of acids, alkalis, and balancing chemical equations. Test your understanding of these essential chemistry topics.