# Units 05–07 Cumulative Benchmark Study Guide

## Structure

- 60 objective questions: 20 each from Units 05, 06, and 07
- Four constructed responses
- Objective mastery: 48/60
- Recommended final mastery: 80/100
- Calculator and blank paper permitted
- Corrections and retakes permitted

## Unit 05 — Ecosystems, Evolution and Biodiversity

Review ecological organization; habitat and niche; food webs; trophic efficiency; matter cycles; biodiversity richness, abundance and evenness; population percent change; mark–recapture assumptions; predator–prey evidence; inherited variation; mutation; natural selection; allele-frequency change; microevolution; reproductive isolation and speciation evidence; the standard biological definition of macroevolution; fossils; equid branching rather than a ladder; observation, measurement, classification, historical inference, methodological naturalism, and worldview interpretation.

Personal belief is not scored. Be able to represent creation, intelligent-design, evolutionary-creation, naturalistic, or undecided interpretations accurately while distinguishing scientific evidence and inference from philosophical or theological conclusions.

## Unit 06 — Atomic Structure and Periodic Patterns

Review elements, compounds and mixtures; Thomson and Rutherford evidence; model revision; proton, neutron and electron charges and masses; atomic and mass numbers; isotope and ion notation; particle counts; weighted atomic mass; standard atomic weight; shell configurations for elements 1–20; periods, groups and valence patterns; Group 1 and Group 17 trends; line spectra; and shell-model limitations.

## Unit 07 — Bonding, Chemical Reactions and Matter

Review electrostatic attraction; ionic and covalent bonds; formula construction and charge balance; polyatomic-ion parentheses; ionic, simple molecular, giant covalent and metallic structures; molecular polarity; relative formula mass; coefficients and subscripts; balanced equations; atom and mass conservation; open versus closed systems; evidence of chemical change; combustion; exothermic and endothermic reactions; activation energy; catalysts; collision theory; temperature effects; dynamic equilibrium; and chemical safety.

## Core Calculations

- Percent change = (final − initial) ÷ initial × 100
- Trophic efficiency = energy transferred ÷ energy available × 100
- Weighted atomic mass = Σ(isotope mass × fractional abundance)
- Neutrons = mass number − atomic number
- Net charge = protons − electrons
- Relative formula mass = sum of relative atomic masses using subscripts
- Balance equations by changing coefficients only
- Shorter completion time for the same reaction extent indicates a faster average rate

## Integration Bridge

Matter cycles through ecosystems and chemical reactions because atoms are rearranged and conserved. Energy is transferred and transformed; usable energy becomes less available through respiration, heat transfer and waste. Chemical potential energy and thermal energy will connect directly to Unit 08.