Earth and Space Science
Solid Earth
Know Earth's layered structure (crust, mantle, outer core, inner core) and that the liquid outer core generates the magnetic field. Plate tectonics explains earthquakes, volcanoes, mountain belts, and seafloor spreading: divergent boundaries create new crust, convergent boundaries produce subduction and volcanoes, transform boundaries slide past one another. The rock cycle links igneous, sedimentary, and metamorphic rocks. Fossils and superposition anchor relative dating, while radiometric decay gives absolute ages.
Atmosphere, weather, climate
Distinguish weather (short-term state) from climate (long-term averages). Uneven solar heating, pressure differences, and Earth's rotation drive winds and storms. The water cycle moves water through evaporation, condensation, precipitation, and runoff. Greenhouse gases trap outgoing infrared radiation; the greenhouse effect is natural, while its enhancement by human emissions drives modern warming.
Space
Seasons result from Earth's 23.5° axial tilt, not distance from the Sun - a very common trap. Moon phases arise from the changing angle between Earth, Moon, and Sun; eclipses require near-perfect alignment and occur only near new or full moon. Know rotation (day) versus revolution (year), the order of the planets, and that stars generate energy by nuclear fusion. The Big Bang model is supported by cosmic expansion and the cosmic microwave background.
Rule of thumb
When a question asks "why," prefer the mechanism that operates globally and consistently: tilt, not distance, for seasons; pressure gradients, not temperature alone, for wind.