Fossils and Relative Dating Quiz

Fossils and Relative Dating

• Fossils are the remains or traces of once-living organisms.
• Not all fossils can be used to determine the relative age of sedimentary rocks.
• Index fossils are remains of plants and animals that existed for a limited time. Desirable index fossils are common, widespread, and easily identified.
• Examples include ammonites, trilobites, and graptolites.
• Relative dating determines the order of geological events without precise dates.
• The principle of fossil succession states a specific fossil assemblage exists only during a particular time period.
• Combined with the principle of superposition—oldest layers are at the bottom, younger ones above—it allows correlation of strata.

The Periodic Table

• The periodic table is an organizational model for elements.
• It encompasses all known elements.
• Arrangement is based on the number of protons (atomic number).
• Johann Dobereiner developed the Law of Triads.
• John Newlands organized the periodic table using the Law of Octaves.
• Dmitri Mendeleev is considered the "Father of the Periodic Table."
• Henry Moseley arranged the table based on the number of protons, and this is the modern standard.
• The table has horizontal rows (periods) and vertical columns (groups).
• Elements are classified as metals, nonmetals, or metalloids.
• Periodic trends predict element properties (valence electrons, atomic radius, ionization energy, electronegativity, electron affinity, oxidizing nature, metallic character).

States of Matter

• Matter is anything that has mass and occupies space.
• It has physical and chemical properties.
• Physical properties don't change the substance's composition.
• Chemical properties relate to changes in a substance's composition.
• Matter can be pure substances (elements and compounds) or mixtures.
• Pure substance examples: salt, water.
• Mixture example: ocean water.
• Physical properties include color, mass, and density.
• Chemical properties include pH and reactivity.
• Corrosion (e.g., rusting) is a chemical property.

States of Matter and Phase Changes

• Matter exists in various states (phases).
• The four common states are solid, liquid, gas, and plasma.
• States are defined by characteristics like energy, density, shape, and volume.
• Examples include solid (ice), liquid (water), gas (water vapor), and plasma (lightning).
• Matter can change phase through processes like melting, freezing, condensation, evaporation, sublimation, deposition, ionization, and deionization.
• These processes involve energy transfer.

Phase Changes

• Phase changes involve energy or pressure changes
• Common phases: solid, liquid, gas.
• Evaporation (liquid to vapor) happens at the boiling point.
• Condensation (vapor to liquid) occurs when a gas loses energy or gains pressure
• Sublimation (solid to gas) skips the liquid phase.
• Deposition (gas to solid) skips the liquid phase
• Freezing (liquid to solid) from loss of energy or increased pressure.
• Melting (solid to liquid) occurs from gaining energy or losing pressure
• Supercritical fluids occur under high pressures & temps with no distinction between liquid & gas
• Critical point is when the vapor-liquid boundary disappears.
• Triple point is the temperature and pressure where all three phases coexist.