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9th-grade-vocabulary-words

English Vocabulary · Grade 9 Live Review Preview

9th Grade Vocabulary Words

Ninth grade marks the transition to high-school reading and writing across literature, argument, research, biology, physical and Earth science, algebra, computing, world history, civics, and geography. This level develops precise academic and domain-specific vocabulary while strengthening context, nuance, source evaluation, figurative language, and evidence-based communication.

This independently authored 800-word beta curriculum is arranged in twenty-three pages of up to thirty-five words. Pages containing words 1–500 include five cloze questions drawn only from that enhanced range; words 501–800 remain fully visible and editable as list pages while the expanded practice layer is developed. Each row includes a subject-field label and an editable word-study note about a transparent affix, compound structure, capitalization, or dictionary base form. The cited Grade 9 resources calibrate difficulty and study skills only; all learner-facing definitions, examples, quizzes, and descriptions are original KSSR copy.

Please note: the vocabulary lists for grades 9~11 have been selected to ensure no overlap with the previous grade level. If the words are too specialized or difficult for you, please go back to grade levels 4~8 and review the words on those pages.

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800 words
Words 281–315 of 800
#WordDetailsMeaningSample sentence
281adaptive radiationnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: adaptive + radiation. Study the complete expression as one field-specific unit.

mukautuva säteilyIsland finches underwent adaptive radiation as they used different foods.
282population dispersionnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: population + dispersion. Study the complete expression as one field-specific unit.

väestön hajontaNesting seabirds show clumped population dispersion along the cliffs.
283environmental resistancenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: environmental + resistance. Study the complete expression as one field-specific unit.

ympäristön kestävyysDisease and food shortage contribute to environmental resistance.
284limiting factornoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: limiting + factor. Study the complete expression as one field-specific unit.

rajoittava tekijäAvailable nesting space is the limiting factor for the colony.
285biotic factornoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: biotic + factor. Study the complete expression as one field-specific unit.

bioottinen tekijäCompetition with an invasive plant is a biotic factor.
286abiotic factornoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: abiotic + factor. Study the complete expression as one field-specific unit.

abioottinen ympäristötekijäSoil pH is an abiotic factor affecting which plants can grow.
287predator-prey relationshipnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: predator + prey + relationship. Study the complete expression as one field-specific unit.

saalistaja-saaliin suhdeChanges in snowshoe hare numbers affect their predator-prey relationship with lynx.
288trophic levelnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: trophic + level. Study the complete expression as one field-specific unit.

trofiatasoAn herbivore occupies a lower trophic level than a hawk.
289energy pyramidnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: energy + pyramid. Study the complete expression as one field-specific unit.

energiapyramidiThe energy pyramid is widest at the producer level.
290biomassnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Base-form focus: biomass is the dictionary headword; compare its inflected or derived forms in context.

biomassaThe grassland contains more plant biomass than wolf biomass.
291nutrient cyclenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: nutrient + cycle. Study the complete expression as one field-specific unit.

ravintoainekiertoDecomposers return matter to the soil in a nutrient cycle.
292nitrogen cyclenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: nitrogen + cycle. Study the complete expression as one field-specific unit.

1. typpi 2. typpikierto 3. typen kiertoBacteria convert atmospheric nitrogen during the nitrogen cycle.
293ecological nichenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: ecological + niche. Study the complete expression as one field-specific unit.

ekologinen lokeroTwo species with an identical ecological niche compete strongly.
294habitat fragmentationnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: habitat + fragmentation. Study the complete expression as one field-specific unit.

elinympäristön pirstoutuminenA highway caused habitat fragmentation in the forest.
295invasive speciesnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: invasive + species. Study the complete expression as one field-specific unit.

haitallinen vieraslajiThe invasive species crowded native mussels off the rocks.
296keystone speciesnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: keystone + species. Study the complete expression as one field-specific unit.

avainlajiSea otters are a keystone species because they limit sea urchins that consume kelp.
297conservation biologynoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: conservation + biology. Study the complete expression as one field-specific unit.

suojelubiologiaConservation biology guides plans for reconnecting wildlife habitat.
298restoration ecologynoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: restoration + ecology. Study the complete expression as one field-specific unit.

kunnostusekologiaRestoration ecology informed the replanting of native wetland grasses.
299ecological resiliencenoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: ecological + resilience. Study the complete expression as one field-specific unit.

ekologinen sietokykySpecies diversity can strengthen ecological resilience after drought.
300ecological successionnoun
Study

Field: Grade 9 life-science and ecology term

Word study: Term structure: ecological + succession. Study the complete expression as one field-specific unit.

ekologinen peräkkäisyysEcological succession began when lichens colonized the bare lava.
301molenoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Base-form focus: mole is the dictionary headword; compare its inflected or derived forms in context.

mooliOne mole of carbon atoms contains Avogadro's number of atoms.
302molar massnoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: molar + mass. Study the complete expression as one field-specific unit.

moolimassaWater has a molar mass of about eighteen grams per mole.
303empirical formulanoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: empirical + formula. Study the complete expression as one field-specific unit.

suhdekaavaThe empirical formula of hydrogen peroxide is HO.
304molecular formulanoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: molecular + formula. Study the complete expression as one field-specific unit.

molekyylikaavaThe molecular formula of hydrogen peroxide is H2O2.
305stoichiometrynoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Root and suffix focus: -metry relates to measuring.

1. stökiometria 2. stoikiometriaStoichiometry predicts how much oxygen is needed to burn the fuel completely.
306chemical equationnoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: chemical + equation. Study the complete expression as one field-specific unit.

1. reaktioyhtälö 2. kemiallinen yhtälöThe balanced chemical equation has the same number of each atom on both sides.
307stoichiometric coefficientnoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: stoichiometric + coefficient. Study the complete expression as one field-specific unit.

stoikiometrinen kerroinThe stoichiometric coefficient 2 indicates two molecules of water.
308reaction mixturenoun
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Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: reaction + mixture. Study the complete expression as one field-specific unit.

reaktioseosThe reaction mixture turned cloudy as a solid formed.
309conservation of massnoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: conservation + of + mass. Study the complete expression as one field-specific unit.

aineen häviämättömyysConservation of mass requires the total reactant mass to equal the total product mass in a closed system.
310limiting reactantnoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: limiting + reactant. Study the complete expression as one field-specific unit.

rajoittava reagenssiHydrogen was the limiting reactant, so some oxygen remained.
311excess reactantnoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: excess + reactant. Study the complete expression as one field-specific unit.

ylimääräinen reagenssiOxygen was the excess reactant and remained after the hydrogen was consumed.
312theoretical yieldnoun
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Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: theoretical + yield. Study the complete expression as one field-specific unit.

teoreettinen tuottoThe calculation gave a theoretical yield of twelve grams.
313actual yieldnoun
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Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: actual + yield. Study the complete expression as one field-specific unit.

todellinen tuottoSome product was lost during filtering, so the actual yield was ten grams.
314percent yieldnoun
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Field: Grade 9 physical, Earth, and environmental-science term

Word study: Term structure: percent + yield. Study the complete expression as one field-specific unit.

prosentin tuottoThe experiment's percent yield was eighty-three percent.
315solubilitynoun
Study

Field: Grade 9 physical, Earth, and environmental-science term

Word study: Suffix focus: -ity commonly forms a noun naming a quality, state, or condition.

liukoisuusThe solubility of many solids increases as water warms.

Vocabulary reading and practice

Page 9 vocabulary review

Review five selected words from page 9.

Vocabulary quiz

Choose the dictionary equivalent for each of 5 selected words.

Sources and curriculum references

These references guide selection and calibration. Definitions, sample sentences, readings, questions, and teaching notes are independently written and reviewed.