CHM135H1 Study Guide - Midterm Guide: Chelation Therapy, Adenylyl Cyclase, Atom
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University of Toronto
Chemistry: Physical Properties
Term Test 1
Electronic Structure of Atoms
- The electronic structure of atoms can be determined through spectroscopy
o Spectroscopy is basically the relationship between electromagnetic radiation and
o Electromagnetic radiation is energy that moves through space in the form of
- Every electromagnetic wave has a wavelength, frequency, and amplitude
o A wavelength (represented by a λ symbol, pronounced ‘lambda’) is the length of
once cycle of a wave, or the distance between two peaks of a wave.
o A frequency (denoted by 𝜈, pronounced ‘nu’) is the number of waves that pass
through a point every second. The frequency is measured in Hz, cycles/s, or s-1.
o The amplitude (denoted by the letter ‘a’), is the height of the wave above OR
below the horizontal axis.
Note: a greater amplitude makes the wave appear brighter. A wave of
visible light, wave A, with the same wavelength and frequency but with a
higher amplitude than wave B will appear brighter. Wave A is brighter
because it has a higher amplitude.
Important equation: 𝑐 = 𝜆𝜈
- Here, 𝑐 represents the speed of light 𝑐 = 3.00×108 𝑚/𝑠
- 𝜆 represents wavelength, and 𝜈 represents frequency
- Note: wavelength and frequency are inversely proportional (as one increases, the other
Before the 1900’s
- Before the 1900’s, matter and light were thought to be completely separate
o Matter was thought to be separate particles. One could determine the mass and
position of those particles.
o Light was thought to be continuous waves, emitted by a light source.
- Diffraction occurs when waves move through a slit
- Interference occurs when two waves come into contact with one another. Interference
can be constructive or destructive, or somewhere in between.
o Constructive interference occurs when two waves that are in phase (i.e. their
peaks line up) with one another, that is, moving in the same direction and with
the same amplitude, wavelength, and frequency. When these two waves come
into contact, they form one wave with twice the amplitude as the previous two