Science: Core Concepts and Data Reasoning
Core skills
Science items sample biology, chemistry, physics, and earth science. Review cell structures and functions, ecosystems and energy flow, states and properties of matter, atomic structure, chemical versus physical changes, forces and motion, energy transfer, simple circuits, and Earth’s systems. Many questions test scientific reasoning: identifying variables, interpreting a described experiment, and distinguishing observations from conclusions.
Common traps
Do not confuse mass with weight, speed with velocity, or heat with temperature. A chemical change produces a new substance; a physical change does not. In circuits, series and parallel arrangements behave differently. In experiments, the independent variable is what is changed, the dependent variable is what is measured, and constants are kept the same. Beware of answer choices that are true statements but do not answer the question asked. Also check units before calculating.
Rule of thumb
Identify the system, the known quantities, and the unit of the requested answer. Use the formula that connects them, then check whether the result is plausible in size and unit.
Worked example
A sample has mass 20 g and volume 5 cm³. Density equals mass divided by volume: 20 g ÷ 5 cm³ = 4 g/cm³. The unit confirms the answer is a density.