Chem 120 (New Update) Introduction to General, Organic Biological Chemistry

Examl3:lChem120/lCheml120l(Newl2025/l
2026lUpdate)lIntroductionltolGeneral,l
Organicl&lBiologicallChemistryl|lQsl&lAs|l
GradelA|
l100%lCorrectl(VerifiedlAnswers)lChamberlain
l

QUESTION
Howlmanylhalfliveslwouldloccurlafterl30lminutesliflalradioactivelmateriallhaslalhalfli
felofl10lminutes?



Answer:
3lHalfllives

HL=l10lminutesl(10lxl3l=l30)




QUESTION
Al60lgramlsampleloflalradioactivelmateriallhaslalhalf-lifelofl5lyears.
Afterl10lyears,lhowlmanylgramslofltheloriginallradioactivelmateriallwilllremain?



Answer:
60lgrams;lwilllundergol2lhalflliveslsincel
10/5=l2
1stlHalflLife:l30lgrams 2ndlHalflLife:l15lgrams

,15lgramslwilllremain




QUESTION
Whenlpolonium-255ldecayslbylpositronlemission,lwhatlislthelproduct?



Answer:
Atomiclnumberldecreaseslbyl1l(atomicl#loflPolisl84,lsol84-1=l83)
Nolchangeltolatomiclmass

Bismuth-225l(hasl83laslatomiclnumber)




QUESTION
Whichloflthelfollowinglarelexamplesloflproteins?

Selectlalllthatlapply

-lAntibodies
-lEnzymes
-lDNA
-lRNA



Answer:
Antibodieslandlenzymesl(DNA/RNAlarelnucleiclacids)

, QUESTION
Chooselthelcarbohydratelthatlislclassifiedlaslalpolysaccharide.