Chemistry, Physics, and Biology Quiz

Write the word equations for the reactions of metals with: Acids: Metal + Acid → Salt + Hydrogen Example: Magnesium + Hydrochloric Acid → Magnesium Chloride + Hydrogen Oxygen: Metal + Oxygen → Metal Oxide Example: Iron + Oxygen → Iron Oxide

Significance of the Reactivity Series & Predictions The reactivity series ranks metals based on their tendency to lose electrons and react. Zinc + Copper Sulfate → Zinc Sulfate + Copper Zinc displaces copper because it is more reactive. Iron + Hydrochloric Acid → Iron Chloride + Hydrogen Iron reacts with acid, producing iron chloride and hydrogen gas.

Metal Extraction Process Example Iron Extraction (Blast Furnace Process): Iron ore (hematite) is reduced by carbon (coke) in a blast furnace, producing molten iron. Fe₂O₃ + 3C → 2Fe + 3CO₂

Comparison of Ceramics, Polymers, and Composites Material Properties Uses Ceramics Hard, brittle, heat-resistant Bricks, tiles, cookware Polymers Lightweight, flexible, non-conductive Plastic bottles, clothing Composites Strong, durable, resistant to corrosion Aircraft, sports equipment

Iron Bridge Exposure Prediction & Prevention Rusting occurs due to oxygen and water → Iron forms iron oxide (Fe₂O₃·xH₂O). Prevention methods: Painting, galvanization (zinc coating), oiling.

Why is aluminum used in aircraft bodies? Lightweight (reduces fuel consumption) Corrosion-resistant (protects against oxidation) High strength-to-weight ratio (maintains structural integrity)

Define 'Periodicity' The repeating pattern of chemical and physical properties of elements across periods.

Comparison of Metals & Non-Metals Property Metals Non-Metals Conductivity Good (heat/electricity) Poor conductors Malleability Malleable Brittle Reactivity React with acids React with oxygen State Mostly solids Gases or brittle solids

Why do elements in the same group exhibit similar properties? They have the same number of valence electrons, leading to similar bonding and reactivity.

Why are noble gases unreactive? They have a full valence electron shell, making them chemically stable.