Chapter 6 notes – Flashcards
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Unlock answers| What is wavelength (λ)? |
| the distance between identical points on successive waves. (units = m or nm) |
| What is amplitude? |
| the vertical distance from the midline of a wave to the peak or trough. (E = 1/λ) |
| What is frequency (v)? |
the number of waves that pass through a particular point in 1 second (Hz = 1 cycle/s = s-1) (s-1 = 1/s) |
| What is the speed of a wave (u)? |
| the product of the wavelength and frequency of the wave. (u = λv) |
| What is the numeric value of the speed of light? |
C = 3.00 x108m/s or 3.00 x1017nm/s |
| In the electromagnetic spectrum what is the order of radiation types from highest to lowest energy order? |
| Gamma rays, X rays, Ultra-violet, Infrared, Microwave, Radio waves |
Calculate the wavelength (in nm) of the red light emitted by a barcode scanner that has a frequency of 4.62 x1014 Hz.
1Hz = 1s-1 |
C = λv λ = C/v λ = (3.00 x1017 nm/s / 4.62 x1014 s-1) λ = 649nm |
| What is Planck's quantum theory equation? |
E = hv E = energy of radiation (J) h = Plancks constant (6.63 x10-34 J.s.) v = frequency of radiation (s-1) |
| What is Plancks constant? |
| 6.63 x10-34 J.s. |
| What is the equation for the photoelectric efffect? |
| E = hc/; |
| The energy required to dislodge electrons from sodium metal via the photoelectric effect is 275kJ/mol. What wavelength in nm of light has sufficient energy per photon to dislodge an electron from the surface of sodium? |
The energy 275kJ/mol is for one mol of photons. To find the energy per photon, we must divide by avagadro's number E = (275kJ/1mol) x (1mol/6.022 x1023photon) x (1000J/1kJ) E = 4.567 x10-19 J/photon E = hc/λ λ = hc/E λ = [(6.63 x10-34- J.s.) x (3.00 x1017 nm/s)] / (4.567 x10-19 J) λ = 436nm |
When copper is bombarded with high-energy electrons, X rays are elimited. Calculate the energy (in joules) associated with the photons if the wavelength of the X rays is 0.154nm. |
E = hc/λ E = [(6.63 x10-34 J.s.) x (3.00 x1017 nm/s)] / (.154nm) E = 1.29 x10-15 J |
| What is Bohr's equation? |
| E(n) = -RH(1/n2) |
| The change in energy when an electron undergoes a transition from one energy level to another is given by what equation? |
;E = -RH [(1/nf2) - (1/ni2)] (RH = 2.18 x10-18 J) |
Calculate the wavelength (in nm) of a photon emitted by a hydrogen atom when its electron drops from the n = 5 state to the n = 3 state. |
;E = -RH [(1/nf2) - (1/ni2)] ;E = -2.18 x10-18 J [(1/32) - (1/52)] ;E = -1.55 x10-19 J E = hc/; ; = hc/E ; = [(6.63 x10-34 J.s.) x (3.00 x1017 nm/s)] / (1.55 x10-19 J) ; = 1280nm |
| What is the de Broglie equation? |
| ; = h/mv |
Calculate the wavelength of an electron traveling with a speed of 2.65 x106 m/s. ; (mass of electron = 9.10939 x10-28 g) (1J = 1kg m2/s2) (h = 6.63 x10-34 J.s.) |
; = (6.63 x10-34 kg m2/s2 s) / [(9.10939 x10-31 kg) x (2.65 x106 m/s)] ; = 2.74 x10-10 m |
Calculate the wavelength (in nm) of a H atom (mass = 1.674 x10-27 kg) moving at a speed of 7.00m/s ; (1J = 1kg m2/s2) |
; = h/mv ; = (6.63 x10-34 kg m2/s2 s) / [(1.674 x10-27 kg) x (7.00 m/s)] ; = (5.66 x10-8 m) x (1 x109 nm/1m) ; = 56.6nm |
| What is the Heinsberg Uncertainty Principle? |
| it is impossible to know simultaneously both the position and momentum of a particle as small as an electron |
| If l = 0, what orbital is it in? |
| s orbital |
| If l = 1, then what orbital is it in? |
| p orbital |
| If l = 2, what orbital is it in? |
| d orbital |
| if l = 3, what orbital is it in? |
| f orbital |
Which set of quantum numbers is permissible for; an electron in an atom? ; a) n =1, l = 1, ml = 0, ms = +1/2 b) n = 3, l = 1, ml = 2, ms = -1/2 c) n = 2, l = 1, ml = 0, ms = +1/2 d) n = 2, l = 0, ml = 0, ms = +1 |
a) n =1, l = 1, ml = 0, ms = +1/2 b) n = 3, l = 1, ml = 2, ms = -1/2 c) n = 2, l = 1, ml = 0, ms = +1/2 d) n = 2, l = 0, ml = 0, ms = +1 |
| What does paramagnetic mean? |
| elements and compounds that have unpaired electrons and are attached to a magnet |
| What does diamagnetic mean? |
| substances in which all electrons are paired and are slightly repelled by a magnet |
| What is the Pauli exclusion principle? |
| no two electrons in an atom can have the same four quantum numbers. |
