Environmental Science Quiz

Chemistry: Exploring the Fundamentals

• An atom is the basic unit of matter, composed of a nucleus surrounded by electrons.
• The nucleus contains protons (positively charged) and neutrons (no charge).
• Electrons (negatively charged) orbit the nucleus.
• The number of protons determines the element.
• The number of neutrons can vary, creating isotopes of the same element.
• The number of electrons in a neutral atom is equal to the number of protons.
• Protons = Atomic Number
• Neutrons = Mass Number - Atomic Number
• Electrons = Atomic Number (neutral atom)
• Chemical properties describe how a substance reacts with other substances, changing its composition.
  • Examples: Reactivity, flammability, pH, solubility.
• Physical properties describe the observable characteristics of a substance, without changing its composition.
  • Examples: State (solid, liquid, gas), color, density, melting/boiling point.

Differentiating Between Pure Substances and Mixtures

• Pure substances consist of a single type of atom or molecule with a fixed composition.
  • Examples: Oxygen (O2), Sodium Chloride (NaCl).
• Mixtures consist of two or more pure substances with a variable composition.
  • Examples: Air, Seawater, Alloys

Characteristics of Elements in the Same Group of the Periodic Table

• Elements in the same group of the periodic table share similar electron configurations and chemical properties, primarily due to having the same number of valence electrons.
• Reactivity is influenced by these shared properties.

Classification of a Newly Discovered Element

• A newly discovered element is classified based on its properties and placement in the periodic table.
• Determining the element's atomic number and mass number, electron configuration and valence electrons are important.
• Comparing the element's properties to those of other elements in the same group and period helps.
• Lastly, assigning the element to the appropriate group and period.

Understanding Metalloids

• Metalloids exhibit properties of both metals and nonmetals.
• They are located along the "staircase" on the periodic table, between metals and nonmetals.
• Examples include Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), and Tellurium (Te).

Counting Atoms in Chemical Compounds

• Subscripts after element symbols indicate the number of atoms of each element in a chemical compound.
• Examples: H2O, CO2, C6H12O6 are used in this process to determine how many atoms are involved in a compound.

Identifying Elements in Chemical Compounds

• Identify elements in compounds by their symbols.
• Example formulas: NaCl, H2SO4, C3H8.

Calculating Density Using GRASS

• Density is mass per unit volume.
• Formula: Density = Mass / Volume
• The GRASS method involves gathering mass and volume data, recording units, and applying the formula to calculate density.

Drawing Bohr-Rutherford Diagrams

• Bohr-Rutherford diagrams are visual representations of an atom's structure.
• Step 1: Determine the element and its atomic number
• Step 2: Draw the nucleus with the appropriate number of protons.
• Step 3: Arrange the electrons around the nucleus in shells, filling the innermost shells first.
• Step 4: Label the shells and indicate the number of electrons in each shell.

Determining Charges After Rubbing Materials Together Using Electrostatic Series

• Rubbing materials together can transfer electrons, causing them to develop opposite electrical charges.
• The electrostatic series (or triboelectric series) lists materials based on their tendency to gain or lose electrons.
• Materials higher in the series tend to lose electrons (become positive).
• Materials lower in the series tend to gain electrons (become negative).

Identifying Elements Based on Given Properties

• Use the periodic table and element properties, such as atomic number, mass number, electron configuration, chemical properties (reactivity, melting/boiling point), and other physical properties, to identify an element.

Properties of a Noble Gas

• Noble gases are extremely stable and unreactive.
• They have full valence electron shells.
• Examples: Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn).

Properties of a Halogen

• Halogens are highly reactive nonmetals.
• They exist as diatomic molecules.
• They have high electronegativity (strong attraction for electrons).
• They form ionic bonds with metals to create salts.
• Examples: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At).

Physics: Circuits, Electricity, and Energy

• Parallel circuits: Components are connected to the same voltage source in multiple paths.
• The current in each branch is independent.
• The total current equals the sum of currents in each branch.
• The voltage across each component is the same.
• Series circuits: Components are connected end-to-end in single paths.
• Current is the same throughout.
• Total voltage is sum of voltages across each component.

Coulomb's Law

• Force between two charges is proportional to the product of the charges and inversely proportional to the square of the distance between them.

Hydroelectricity

• Hydroelectricity is a renewable energy source using flowing water to generate electricity.
• Advantages include renewability and low operating costs.
• Disadvantages involve specific geographic locations and potential environmental impact.

Resistance and Non-Renewable Resources

• Resistance in wires is affected by length, cross-sectional area, and material of the wire.
• Non-renewable resources are natural resources that cannot be replenished at the same rate they are consumed. (e.g. fossil fuels, minerals, nuclear fuels)

Ecology: Understanding the Process of Photosynthesis, Characteristics of Earth's Spheres, and Sustainable Practices

• Photosynthesis: the process by which plants convert light energy into chemical energy (glucose)
  • Occurs in chloroplasts, specifically thylakoids.
• The overall equation for photosynthesis is: 6CO2 + 6H2O → C6H12O6 + 6O2
• Light dependent reactions split water, produce ATP and NADPH.
• Light independent reactions use ATP and NADPH to convert CO2 into glucose.
• Earth's spheres: lithosphere (solid), hydrosphere (water), atmosphere (gases), biosphere (life).

Analyzing Food Chains and Webs

• Food chains and food webs show the energy flow and relationships in an ecosystem.
• Identify producers, consumers, decomposers and trophic levels.
• Understand energy flow and transfer, and interconnectedness within the ecosystem.

Earth and Space: Hertzsprung-Russell Diagram, Galaxies, Comets, and More

• Hertzsprung-Russell (H-R) diagram plots the relationship between a star's absolute magnitude and spectral classification (color).
• It's a fundamental tool in stellar astronomy.
• Absolute Magnitude: Intrinsic brightness of a star (if at 10 parsecs).
• Spectral Classification: A scheme to categorize stars based on their surface temperature (O-type is hottest, M-type is coolest).
• Main Sequence: Diagonal band on the H-R diagram where most stars are found, fusing hydrogen into helium.
• Giant stars: Expanded and cooled stars off the main sequence.
• Dwarf stars: Smaller and denser stars occupying the lower left portion of the H-R diagram.
• Galaxies: Clusters of stars, dust, gas, held together by gravity.
  • Spiral, elliptical, irregular galaxies.
• Comets: Small icy objects orbiting the sun.
  • Nucleus, coma, tail based on the movement around the sun.

Identifying Terrestrial Planets

• Terrestrial planets are small, rocky planets closer to the sun.
• Examples of terrestrial planets include Mercury, Venus, Earth and Mars.
• The characteristics of each planet vary.

Conditions for a Lunar Eclipse

• Lunar eclipse: Moon passes through Earth's shadow.
• Conditions: Full moon phase, moon passing through Earth's umbra (full shadow).