(ip) science notes s1 2020

LeeCaiWei103'2020 natureof sciencetheswonkypartsCONPTTGridConsistentWhenobservations/experimentsarerepeatedunderthesameconditions,theresultsarereasonablythesame.ObservableThephenomenonorevidencecanbeobservedbyhumansensesoranextensionofthosesenses.(egmicroscope)NaturalAnaturalcauseornaturallyoccurringmechanismisusedtoexplainhoworwhyaneventhappens.PredictableAccuratepredictionsarebasedononlynaturalcauses,notonpresupposedorassumedinformation.TestableControlledexperimentscanbedesignedtotestthenaturalcauseoftheeventorphenomenon.TentativeExplanationsofthecauseofthephenomenonaresubjectedtochangewhennew(legit)evidenceoccurs. ScientificMethodObservationQuestionHypothesisExperimentAnalysisCommunication thenot soswonkyparts Safetyrules-Safetyrule Reason Wearyourownsafetygoogleswhenusingchemicalsorwhenheating. Protectseyesfromharmfulfumesandchemicalsorliquidthatmayaccidentallypourfromatesttubeduringheating. Donotputsolidwastenorpourconcentratedchemicalsintothesink. Thisistopreventcorrodingthesinkandthechemicalsfromreactingwithoneanotherwhileinthesink.Toalsopreventcloggingupofsink(solidwaste) Donotclosealldoorsandwindowswhenusingthelaboratory. Goodventilationwillpreventtheaccumulationoffumesofgases(fromchemicalreactionsorgassupply)whichmaymakeusfeelunwell.

LeeCaiWei103'2020 Donottasteanychemicals. Toavoidconsumingdangerouschemicalsthatmaybeharmful. Bunsenburner Closedairhole-luminousflameOpenairhole-non-luminousflameLuminousflame-Unsteady-Visible-Yellowcolouredflame Non-luminousflame-Steady-Notvisible-Bluecolouredflame LeaveworkstationforafewminuteswhilehavingBunsenburneron-Turnflamefromnon-luminousflametoluminousbyclosingairhole

LeeCaiWei103'2020 physical propertiesMetal-malleable,goodelectricalconductivity,goodthermalconductivityCeramic-hard,brittle,highmeltingpointGlass-transparent,brittle,poorelectricalconductivityPlastic-donotcorrode/non-biodegradable,poorelectricalconductivity,poorthermalconductivityFibre-elastic,poorelectricalconductivity,poorthermalconductivity Aphysicalpropertyisanypropertythatcanbeobservedormeasured. Aphysicalquantitycanbequantifiedbymeasurementandismadeupofanumericalmagnitudeandaunit. basephysicalquantities SIbaseunits length metre(m) mass kilogram(kg) time second(s) (thesearethecommonones👀 ) prefix howmuchitrepresents mega(M) 10 6 kilo(k) 10 3 centi(c) 10 -2 milli(m) 10 -3 UncertaintyofareadingHalfofsmallestdivision:e.g.thermometer,measuringcylinder(alsoprecision) Density=mass/volume averagedensity=totalmass/totalvolume

LeeCaiWei103'2020 chemical compositionElements● puresubstancesthatcannotbebrokendownfurtherintosimplersubstancesusingchemicalprocesses● containsonlyonetypeofatom● metalsfromperiodictablegrp1-3● metalloids● non-metalsfromgrp5-8● puresomeltandboilatfixedtemp Compounds● aremadeoftwoormoretypesofatomschemicallycombinedtogether● hasafixedproportionofeachelementbymass● formedfromelementsbychemicalchange● puresomeltandboilatfixedtemp● propertiesaredifferentfromelements● canbeseparatedbychemicalmethodsthosoyay:) Mixture