3 syllables:
chemistry, kemistry

4 syllables:
alchemistry

5 syllables:
astrochemistry, bio-chemistry, biochemistry, cosmochemistry, cytochemistry, femtochemistry, geochemistry, histochemistry, macro-chemistry, metachemistry, micro-chemistry, microchemistry, nanochemistry, neurochemistry, petrochemistry, photochemistry, phytochemistry, psychochemistry, pyrochemistry, sonochemistry, spectrochemistry, thermochemistry, zoochemistry

6 syllables:
actino-chemistry, actinochemistry, electro-chemistry, electrochemistry, iatrochemistry, magnetochemistry, mechanochemistry, organic chemistry, physical chemistry, piezochemistry, radiochemistry, stereo-chemistry, stereochemistry

7 syllables:
biogeochemistry, department of chemistry, inorganic chemistry

8 syllables:
immunocytochemistry, immunohistochemistry, interpersonal chemistry

2 syllables:
thessaly

3 syllables:
pregnancy, flexibly, melody, legatee, steadily, severally, splendidly, pleasantly, entity, legacy, bestially, cecity, felony, necropsy, messily, preciously, jealousy, restfully, recipe, sesame, enemy, ecstasy, tendency, seventy, entropy, ebony, especially, debauchee, pedigree, credibly, specialty, presently, gemini, destiny, venally, zealotry, mentally, density, heavily, tensity, leprosy, dreadfully, helpfully, prelacy, peasantry, lengthily, heavenly, elegy, readily, testily, specially, clemency, medically, embassy, tenantry, endlessly, weaponry, velvety, helplessly, empathy, tenancy, equity, pleasantry, zestfully, centrally, jealously, chemically, penalty, threnody, sensibly, kennedy, devilry, deputy, remedy, breathlessly, brevity, secondly, revelry, pedantry, enmity, benghazi, dextrously, ectropy, emigree, evilly, fecklessly, jejunely, legibly, lemony, lenity, melanie, pebbly, pederasty, penally, resiny, self-pity, selflessly, senselessly, sentiency, stephanie, tepidly, trenchancy, trepidly, vengefully, yemeni, zestily

4 syllables:
inflexibly, dependency, supremacy, convexity, theosophy, incredibly, fidelity, unpleasantly, integrity, nephrectomy, incessantly, potentially, rebelliously, transcendency, death penalty, allegedly, detestably, anemone, longevity, acceptably, tremendously, repentantly, ineffably, resplendently, essentially, extremity, flux density, ascendancy, desperately, nonentity, mastectomy, schenectady, lumpectomy, indemnity, expectancy, perplexity, intrepidly, vasectomy, ostensibly, identity, incessancy, necessity, dependably, sententiously, resplendency, lamentably, complexity, solemnity, successfully, splenectomy, inequity, contemptuously, amenity, discrepancy, sequentially, federally, unsteadily, separately, telepathy, intensity, insensibly, telemetry, respectfully, lobectomy, ascendency, preferably, licentiously, low density, regrettably, respectably, thrombectomy, hegemony, heredity, tentatively, generally, infectiously, perceptibly, penelope, serenity, acephaly, confessedly, defencelessly, domenici, forelady, illegibly, immensity, impendency, impetuously, inclemency, jack kennedy, lieutenancy, neurectomy, perplexedly, polemically, pretentiously, professedly, quiescency, refreshfully, relentlessly, revengefully, shell entity, unhelpfully, vulvectomy, with empathy

5 syllables:
disrespectfully, appendectomy, penitentially, high fidelity, prostatectomy, tonsillectomy, irreverently, orchidectomy, macrencephaly, unacceptably, deferentially, confederacy, mask of pregnancy, independency, accidentally, mastoidectomy, independently, conscientiously, tubal pregnancy, embolectomy, abstemiously, microcephaly, rhytidectomy, reverentially, fundamentally, hysterectomy, oophorectomy, incidentally, vapor density, eventually, white supremacy, anencephaly, professionally, sympathectomy, stapedectomy, reprehensibly, orchiectomy, pneumonectomy, unsuccessfully, salpingectomy, intemperately, life expectancy, open sesame, sentimentally, providentially, thyroidectomy, exceptionally, consequentially, acrocephaly, change integrity, change intensity, clinocephaly, coalescency, create mentally, detrimentally, drunken revelry, field intensity, half-intensity, high-fidelity, hydrocephaly, intumescency, laminectomy, laryngectomy, line of destiny, macrocephaly, megacephaly, meniscectomy, mortal enemy, mountain ebony, nanocephaly, naval weaponry, of necessity, scaphocephaly, school of dentistry, sigmoidectomy, unforgettably, unpretentiously, unrepentantly

6 syllables:
cholecystectomy, unconventionally, experimentally, interdependency, simple mastectomy, coincidentally, biogeography, impetuosity, unintentionally, cosmetic dentistry, inconsequentially, manifest destiny, adrenalectomy, environmentally, relative density, cercopithecidae, adenoidectomy, anas penelope, appendicectomy, change of integrity, genus penelope, militant tendency, ovariectomy, panhysterectomy, pedal extremity, unsentimentally

7 syllables:
radical mastectomy, abdominal pregnancy, total hysterectomy, ovarian pregnancy, magnetic flux density, paleogeography, executive clemency, feeling of identity, john fitzgerald kennedy, magnetic intensity, suprarenalectomy

8 syllables:
radical hysterectomy, conformational entropy

10 syllables:
modified radical mastectomy