Science Review Chemistry Chapters 1-5

Scientific Notation Form – #.### x 10 exp – #s are all significant figures Exponents – Negative for # between 0 & 1 – Zero as the exponent for #s 1 to … – Positive for # of 10 or higher Rule of exponents: (10 A )(10 B ) = 10 A+B (10 A )/ (10 B ) = 10 A-B

Significant Figures All #s 1–9 All zeros between # 1-9: 409; All zeros after #s 1-9 after the decimal point – 19.00; Rules: – Product or Quotient has no more S.F. than the least # of S.F. in the problem – Sum or Difference has no more decimal places than the least # decimal places in the problem

SI units Value, Symbol, & Name o 10 9 = G = giga = M = mega- o 10 3 = k = kilo = h = hecta- o 10 1 = da = deca = d = deci- o = c = centi = m = milli- o =  = micro = n = nano- o = p = pico-

SI Base Units & Derived Units Mass (kilogram); Length (meter); Temperature (Kelvin); Time (second); Current (ampere); Luminosity (candella) Derived units have more than 1 SI base unit – Velocity (m/s); Volume (Liter; cm 3 ); Force (N); Density (kg/cm 3 ); Acceleration (m/s 2 ); Area (m 2 ); Pressure (Pa) …

Scientific Method Steps – Observation: senses & technology – Form hypothesis: proposed explanation – Gather information: people, publications, Internet – Plan & perform experiment: constants, control, independent variable, & dependent variable – Record & analyze data: statistics, graph, chart, words – Conclude &/ or modify hypothesis – Support or disagree with standing theory

Measurements & Calculations Quantitative vs. Qualitative: #s vs. words Precision vs. Accuracy: grouping vs. accepted # Research & Technology Basic research – increases knowledge Applied research – solve a problem Technological development – production & use of items to improve quality of life

Branches of Chemistry Organic: carbon-containing compounds Inorganic: non-organic substances Physical: properties &  s of matter & their relation to energy Analytical: id components & composition Biochemistry: living substances & processes Theoretical: math & computers to understand underlying principles and to predict properties

Matter & Its Properties Matter = anything with mass & volume Properties – Extensive = depends on amount of matter present – Intensive = doesn’t depend on amount of matter – Physical = can be measured without  in identity States of matter – Chemical = measuring will  identity Chemical reactions

Classification of Matter Substance vs. Mixture – Substance: Element vs. Compound – Mixture: Homogeneous vs. Heterogeneous Mixtures: Solution vs. Colloid vs. Suspension – Solutions are homogeneous. Two Tests: Filtration & Tyndall Effect – Solution: no filtration & no Tyndall effect – Colloid: no filtration but has Tyndall effect – Suspension: yes to both filtration & Tyndall effect

Types of Elements Metals – Alkali, alkaline earth, transition, & rare-earth – Malleable, ductile, shiny, conduct heat/ electricity – Mobile sea of electrons Metalloids – Semi-conductor; in between properties Nonmetals – Poor conductor of heat/ electricity, dull, brittle Noble gases – inert/ nonreactive

Atoms Democritus coined term in 400 B.C. Dalton’s Atomic Theory – Atoms compose all matter. – An element’s atoms are identical is size, mass, & properties. {Didn’t know about isotopes} – Atoms cannot be subdivided, created, or destroyed. {Didn’t know about fusion or fission} – Atoms of different elements combine in simple whole-number ratios. – Atoms combine/ separate/ rearrange in reactions

Structure of Atom Proton: 1 amu; (+) charge; Goldstein found it using cathode ray tube Neutron: 1 amu; no charge; Chadwich Electron: 0 amu; (-) charge; Thomson found it with cathode ray tube; Millikan measured charge & mass; Bohr proposed concentric electron orbitals Nucleus: composed of protons & neutrons; Rutherford found it using gold-foil experiment

Counting Atoms Atomic Number = # of protons Mass Number = # of protons + # of neutrons Average Atomic Mass = Weighted average of all naturally found isotopes of that element Molar Mass = grams/ mole – Noted on periodic table under the symbol of the element – Mole = same # of atoms of C-12 in 12 grams of C-12 Avogadro’s number = x particles/mole Relative atomic masses – Noted on periodic table (Same # as the molar mass) – amu = atomic mass unit – 1 amu = 1/12 of Carbon-12’s mass

Electron Configuration Bohr’s line-emission spectrum & the photoelectric effect  dual nature of light – Light is not only a wave but also a particle. Photon = particle of electromagnetic radiation having 0 mass & carrying a quantum of energy Electrons behave as waves. – Schrodinger’s wave equations & Heisenberg’s uncertainty principle  quantum theory

Quantum Numbers Principal Quantum Number – Designated as “n” – Indicates main energy level electron occupies Angular Momentum Quantum Number – Designated as “l” – Indicates shape of orbital (s, p, d, f) Magnetic Quantum Number – Designated as “m” – Indicates orientation of orbital (x, y, z, xy, z 2, yz, …) Spin Quantum Number – Designated as “s” – Indicates spin (clockwise = + ½, counterclockwise = - ½)

Electron Configuration Rules – Aufbau principle: e - occupies lowest-energy level – Pauli exclusion principle: no 2 e - have same 4 Q.N. – Hund’s rule: orbitals of equal energy each receive 1 e - before any receives 2 Types – Electron-configuration notation 1s 2 2s 2 2p 6 3s 1 = Na 1s2s2p3s3p4s3d4p5s4d5p6s4f5d6p7s5f6d7p; s 2 p 6 d 10 f 14 max – Noble gas configuration [Ne]3s 1 = Na – Orbital notation = He

Periodic Properties’ Trends Atomic & ionic radii: as go left & down – This is due to increase in nuclear charge. Ionic radii: cations are Ionization energy: energy to remove e - from neutral atom; as go right & up Electron affinity: energy when e - is acquired; most atoms release energy when get e - ; negative #s as move right & up Electronegativity: ability to attract e - in cpd; F has highest & Fr/Cs has lowest.