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, immunochemistry, magnetochemistry, mechanochemistry, organic chemistry, physical chemistry, piezochemistry, radiochemistry, stereo-chemistry, stereochemistry

7 syllables:
biogeochemistry, department of chemistry, inorganic chemistry

8 syllables:
immunocytochemistry, interpersonal chemistry

2 syllables:
swiftly, crisply, gristly, bristly, christly

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

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

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

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

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

8 syllables:
conformational entropy, radical hysterectomy

10 syllables:
modified radical mastectomy