Chemistry Chapter 1Part 1● Key Idea: The properties of matter depend on the types and arrangement of atoms andmolecules.● Matter is divided into mixtures and substances. Substances are divided into elementsand compounds.● Elements: The most basic units of matter. There are substances composed of only oneatom. Anything on a periodic table is an element. Can’t be broken down.● 90% of our bodies are made of oxygen, carbon, and hydrogen.● Atom: Smallest chemical unit of matter or indivisible unit of an element.● Molecule: 2 or more atoms formed chemically.● Compounds: Combination of two or more atoms of different elements bonded together.Can be broken down.○ The physical and chemical characteristics of the compounds generally differ fromthe properties of the individual elements that constitute the compound● Pure Substance: A collection of matter that has the same chemical compositionthroughout. Can be a molecule, atom, or compound, but can only consist of one species.● States of matter: Solid, liquid, gas, can change when energy is added or removed.● Physical change: Change in a physical property of a substance.● Physical properties: Density, color, melting point, boiling point, condensation,evaporation, dissolving, viscosity.● Chemical properties: Combustion, rusting, tarnishing, oxidation, reduction, addition,stability.● Chemical change: Change in chemical composition of a substance.● Mixture: Substance made up of two or more elements or compounds that have notchemically reacted.● Homogenous mixture: Mixture that has a uniform composition.● Heterogenous mixtures: Mixture that does not have a uniform composition.Part 2● Metric SystemBase UnitsSI UnitSymbolLengthMetermMassKilogramkgTimeSecondsElectric currentAmpereATemperatureKelvinKAmount of substanceMolemolLuminous intensityCandelacdVolumeNAm^3(cubic meter)DensityNAkg/m^3●PrefixAbbreviationFactormegaM1,000,000 (10^6)kilok1000 (10^3)decid.1 (10^-1)centic.01 (1-^-2milim.001 (10^-3)microm10^-6nanon10^-9picop10^-12● K = C(degrees) + 273.15● F = 1.8 * C(degrees) + 32● Significant Figures: Certainty in measurement is limited by instrument used.● Rules:a. Zeroes between non-zero digits are always significant.■ Ex: 1005(4 sig figs)b. Zeroes at the beginning of a number never count.■ Ex: .02(1 sig fig)c. Zeroes at the end of a number are significant if the number has a decimal point.■ Ex: 3.0(2 sig figs)d. When adding or subtracting, answers should have the same number of decimalplaces as the value w/ the fewest decimal places.e. When multiplying and dividing, the answer should have the same number of sigfigs as that with the fewest sig figs.f. When the answer contains more than the correct number of sig figs, it must berounded off.● Precision: How close measurements are to one another.● Accuracy: How close measurements are to true