Matter & Reactions
What is the law that says the total number of atoms of each element is the same before and after a chemical reaction?
Conservation of mass / conservation of atoms in chemical reactions (mass is conserved).
Name one energy store (type of energy) and one way energy can be transferred from that store to another.
Examples:
-Chemical potential energy in a battery → electrical energy when connected in circuit
-gravitational potential → kinetic when object falls.
What type of data would you analyze to determine the relative age of rock layers and fossils?
Relative dating data: rock layer sequences, superposition, index fossils, cross-cutting relationships.
What is the difference between a trait inherited from parents and a trait resulting from a mutation?
Inherited trait: passed via alleles from parents (e.g., eye color). Mutation: change in DNA sequence that may produce a new trait not present in parents.
True or False: A scientific theory is just a guess and cannot be supported by evidence.
False
Give an example of a physical property and a chemical property used to identify a substance.
density, color, melting point; Chemical property example: reactivity with acid, flammability, oxidation.
Define wavelength and frequency for a wave and state how they are related qualitatively.
Wavelength = distance between repeating points; frequency = number of waves passing per second. Higher frequency → shorter wavelength for a given wave speed
Name one human activity that can change the biosphere by affecting limited natural resources.
Examples: mining, deforestation, overfishing, groundwater overuse — these reduce resources and alter habitats.
Give one example of a technological advancement that has furthered genetic research and one positive and one negative effect of that advancement.
Example: CRISPR gene editing — Positive: can correct genetic diseases; Negative: ethical concerns, potential off-target effects or unintended ecological impacts.
Name two types of data that can be collected during an investigation.
Qualitative and quantitative.
Describe, in one sentence, how atoms are rearranged during a chemical reaction to form a new compound
Atoms break bonds in reactants and form new bonds to make products; atoms themselves are neither created nor destroyed.
Explain how changing the amplitude of a wave affects the energy the wave carries.
Larger amplitude generally means more energy carried by the wave (e.g., sound louder, water waves more energetic
Explain how fossil distribution and continental shapes provide evidence for past plate motions.
Matching fossil types and rock strata across continents and complementary continental coastlines indicate continents were once joined and moved apart (plate tectonics)
Describe how natural selection can cause the frequency of a trait to increase in a population over several generations.
Individuals with beneficial traits survive/reproduce more, passing alleles to offspring; over generations allele frequency rises, increasing trait prevalence.
What is a variable? Give an example of an independent and a dependent variable in a plant growth experiment.
Variable = factor that can change. Example: independent = hours of light; dependent = plant height.
You are given a balanced chemical equation. Explain why mass is conserved using the particle (atom) model.
Balanced equation shows equal counts of each element on both sides; particle model: same number of each atom rearranged into product molecules so total mass unchanged.
Sketch or describe a mathematical model that relates wave speed, wavelength, and frequency. (Write the formula.)
Formula: v=fλv=fλ where vv is wave speed, ff is frequency, and λλ is wavelength
Given data showing occurrences of a particular natural hazard over time, what two pieces of information would help you predict where and when it might happen next?
Use frequency (how often events occurred) and spatial distribution (where events occurred), plus trends (increasing/decreasing) and precursors (e.g., small quakes before larger ones) to forecast
Outline a simple model showing how genetic variation and selection can lead to the formation of a new species (speciation) over time.
Model outline: population with variation → geographic/behavioral isolation reduces gene flow → different selective pressures lead to divergence in traits → reproductive isolation develops → speciation.
Give an example of a scientific model being used to generate data for testing an engineered solution.
Example: climate models used to simulate wind loads for turbine design; models generate data for testing.
Devise a simple classroom model (materials and steps) that demonstrates how molecules can be rearranged during a chemical reaction while conserving the number of each type of atom
Example model: use colored balls (atoms) and Velcro bonds on cardboard molecules. Show reactant molecules, then separate and recombine balls to form product molecules while counting each color to show conservation.
Propose one modification to increase the efficiency of energy transfer in a simple system (for example, improving heat transfer from a stovetop to a pot) and justify it using energy concepts.
Example solution: Add an insulating layer between heat source and pot or improve thermal contact (increase surface area/contact). Justification: reduces heat loss and lowers wasted energy, increasing transfer efficiency.
Design a short argument (3–4 sentences) that explains how human consumption of a limited resource could cause long-term impacts on an ecosystem.
Example argument: Overuse of groundwater lowers water tables, reducing plant growth and altering species composition; this decreases biodiversity and can cause soil compaction and erosion, harming long-term ecosystem services.
Evaluate a brief scenario: A population of insects is exposed to a pesticide. A small fraction carry a mutation that provides resistance. Over many generations the pesticide no longer kills the insects. Explain the steps, using genetic variation, selection, and evidence, that lead to this outcome.
Steps: initial variation due to mutation; pesticide kills susceptible insects; resistant individuals survive and reproduce; allele frequency for resistance increases; after many generations, majority carry resistance—evidence: change in survival rates, genetic tests showing mutation frequency increase.
Describe how measurement tools (technology) extend scientific investigations; include a specific example (e.g., microscopes, sensors).
Microscopes reveal cell structure enabling biomedical research; sensors record precise temperature enabling controlled experiments.