2 MATTER & ENERGY Matter Anything that occupies space and can be weighed Chemistry examines the nature of matterEnergyNo massAbility to do workMatter is the substance that is moved by energy
3 Matter Building blocks: solid, liquid, gas Physical change –nature of substance is unchangedChemical change –nature of substance is changed
4 ENERGY No mass We measure the effect of energy on matter Two types: Kinetic and Potential
5 ENERGY Forms: Chemical -stored within bonds, released as heat Electrical -movement of charged partials (e-)Mechanical -direct movement of matterRadiant -electromagnetic wavesEnergy is converted from one form to another, any not used is released as heat.
6 COMPOSITION OF MATTER Elements Atoms Opposites attract! Protons (p+) –positive chargeNeutrons(n0) –neutral or no chargeElectrons (e-) –negative chargeOpposites attract!
8 ATOMS Orbital Model –electron cloud Atomic number –number of protons Atomic mass –sum of all protons and neutronsIsotopes –vary in number of neutronsRadioisotopes –radioactivity, heavy isotopes
9 CHEMICAL BONDS & REACTIONS Molecules, Compounds, Reactions, OH MY!Molecules =sameCompounds =differentReactions =associations or dissociations of atomsBonds form between molecules and compoundsEnergy relationships
10 CHEMICAL BONDS Bonds are energy relationships Opposites attract while “like” or same repelsRole of electronsOccupy fixed regions called electron shells or energy levelsValence shell electrons participate in bonds