JinwanReviewMidterm1

# JinwanReviewMidterm1 - TonyNguyen,JinwanKim...

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Tony Nguyen, Jinwan Kim Chem 1A – Arasasingham Midterm 1 Review Nuclear Model of an Atom There are 3 subatomic particles, each with a different charge, they are: o Protons (+) o Neutrons (0) o Electrons (-) Notation Atomic number (Z) = # protons Mass number (A) = # protons + # neutrons Isotopes and Atomic Mass isotopes – atoms with same atomic number (Z) but different mass number (A) atomic mass – mass of a given isotope – the total mass of protons, electrons, neutrons in one atom One atom of carbon-12 has an exact value of 12 amu (atomic mass unit) Relative Abundance – the percentage of a naturally occurring isotope. You use this information to calculate average atomic mass. Avogadro’s number Using mass spectrometry, the number of atoms in exactly 12 g of carbon-12 was found to be 6.022 x 10 23 . Avogadro’s constant (N a ) = 6.022 x 10 23 atoms / mol. Number of atoms = ( moles ) ( atoms / mol ) Molar Mass (Na) (MM) # atoms  # moles  mass Quantum Chemistry Electromagnetic radiation – oscillating electric and magnetic fields that travel through empty space at 3.00 x 10 8 m/s Wavelength (λ) – peak to peak distance (UNITS: m or nm) amplitude – height of the wave frequency (ν) – number of oscillations per second (UNITS:Hz = s -1 ) IMPORTANT EQUATION: wavelength x frequency = speed of light o λv = c

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Tony Nguyen, Jinwan Kim Chem 1A – Arasasingham Midterm 1 Review inverse relationship between wavelength and frequency o short wavelength = larger frequency and vice versa Energy of a Photon Exchange of energy between matter and radiation occurs in quanta, or packets of energy Atoms oscillating at a frequency, v (nu) can exchange energy with its surroundings IMPORTANT EQUATION 2: Energy of a photon = Planck’s Constant x frequency E = hv Photoelectric Effect Ejection of electrons from a metal when its surface is exposed to UV radiation Details: o No electrons are emitted unless it has a
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## This note was uploaded on 11/19/2010 for the course CHEMISTRY Chem 1A Di taught by Professor Rameshdarasasingham during the Spring '10 term at UC Irvine.

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JinwanReviewMidterm1 - TonyNguyen,JinwanKim...

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