2 ElementsElementsA substance that can not be broken down into simpler chemical substancesThe Periodic Table lists all known elements
3 Atoms: The Building Blocks of Elements Smallest particle of an element that has the characteristics of that elementStructure of an AtomNucleusProtons (Positive)Neutrons (Neutral)Energy levels(outside of the nucleus)Electrons (Negative)
4 How come atoms do NOT have a charge? In an atom, the number of electrons equals the number of protons.So the number of positive and negative charges balance out, giving the atom a charge of 0.
5 Fill in the following chart: ParticleLocationChargeSymbolElectronoutside of nucleusIn energy levelsnegativee-ProtonInside the nucleuspositivep+Neutronneutraln0
6 Energy Levels First energy level Second energy level 2 electronsSecond energy level8 electronsThird energy level18 electronsRules for filling in energy levels!The first energy level has to be FULL before electrons can go into the 2nd energy levelThe 1st and the 2nd energy level has to be FULL before electrons can go into the 3rd energy level
7 CompoundsCompounds are substances made of 2 or more elements that form a molecule (2 or more atoms together).Examples of common compounds:Table Salt - NaClOxygen gas – O2Water – H2O
8 Properties of Compounds Compounds have BONDS between the atomsIt is difficult to separate the parts of a compoundCompounds have chemical formulas to tell you what elements are found in the compound and how many atoms of each element are present.The chemical formula for water is H2O. There are two atoms of hydrogen and one of oxygen.
9 Ionic Vs. Covalent Bonds Ionic BondsForm when electrons are exchanged between atoms.Covalent BondsForm when electrons are shared between atoms.Both types of bonds result in all atoms having a full outer energy level.
10 Chemical ReactionsChemical reactions happen when bonds are formed or broken and recombine to form new compoundsAll chemical reactions that occur within an organism are referred to as that organism’s metabolism.
11 MixturesMixtures are combinations of 2 or more pure substances or compoundsSome common mixtures:Iced TeaDirtPaint
12 Properties of Mixtures There are NO BONDS holding mixtures togetherMixtures can often be separatedMixtures can occur in any proportions and DO NOT HAVE A SET FORMULA and can use different components
13 SolutionsSolution – mixture of one or more substances uniformly distributed in another substance.Can be solid, liquid, gasex. Plasma (liquid)brass (solid) copper and zincsoda (liquid/gas) water and CO2
14 Acids & BasesThe Homeostasis of living things depends on the degree of acidity (acid) and alkalinity (base) in certain areas
15 Acids & Bases Acids= any substance that forms hydrogen (H+) in water. Alkalinity (a/k/a basic solution)= any substance that forms hydroxide ions (OH-) in water
16 Acids - pH < 7 Sour taste Corrosive on metals Burns skin Ex. Orange juice,vinegar, sulfuric acid*Homeostasis relevance- your stomach must have a certain acidity to function properly
17 Bases Tastes bitter Slippery Irritate the skin Ex. NaOH -pH > 7Tastes bitterSlipperyIrritate the skinEx. NaOHHomeostasis relevance-your small intestine needs a certain alkalinity (basic) to function properly
18 pH Scale Tells you how acidic or basic something is Ranges 0-14 7 = neutralabove 7 = basebelow 7 = acidTen fold systemMeasure pH with litmus paper