Study

Electrons and Energy Review

  •   0%
  •  0     0     0

  • In electromagnetic wave calculations, what is "h"?
    Planck's constant= 6.626 x 10^-34 Jxs
  • What is the maximum number of electrons that can occupy energy level 5?
    18
  • What is Planck's constant?
    h = 6.626 x 10^-34 Jxs
  • The atomic emission spectra uses which part of the Electromagnetic (EM) spectrum?
    visible light
  • Visible light has a wavelength between _________ - __________ (approximately).
    400 nm to 750 nm (4.00x10^-7 m to 7.50x10^-7 m)
  • True or False: Elements in the same group/family have similar chemical properties?
    True
  • How many valence electrons does every element in group/family 14 of the periodic table have?
    4
  • How many valence electrons does every element in group/family 17 of the periodic table have?
    7
  • In electromagnetic wave calculations, what is "c"?
    speed of light= 3.00x10^8 m/s/s
  • What formula would you use to solve the following problem?: Calculate the energy of an EM wave with a frequency of 5.00x10^14 Hz.
    E=hv
  • How does an electron become "excited"?
    The electron absorbs energy and jumps to a higher energy level.
  • True or False: Elements in the same period have similar chemical properties?
    False
  • True or False: Electrons move in circular paths around the nucleus of the atom.
    False
  • Why can atomic emission spectra be used to identify unknown samples?
    because the wavelengths emitted from each element are unique to that element (the color flame is unique to the element)
  • Describe what caused the colored flames in the flame test lab.
    electrons absorbed energy from the flame; jumped to higher less stable energy level; released energy as they fell back to ground state
  • What element is in the 3rd period and has 2 valence electrons?
    Magnesium (Mg)
  • How many valence electrons does every element in group/family 2 of the periodic table have?
    2
  • What is the frequency of a wave whose wavelength is 5.25x10^-7 m? (include proper units in your answer)
    c=λv -->v=c/λ=(3.00x10^8)/(5.25x10^-7)= 5.71x10^14 Hz
  • What formula would you use to solve the following problem?: Calculate the wavelength of an EM wave with a frequency of 5.00x10^14 Hz.
    c=λv
  • What is the maximum number of electrons that can occupy energy level 6?
    32
  • What is the unit for energy?
    Joules (J)
  • What color of visible light has the smallest amount of energy? the greatest amount of energy?
    smallest: red; largest: purple/pink
  • What is the energy of a photon whose frequency is 3.9x10^14 Hz? (include proper units in your answer)
    E=hv=(6.626x10^-34)(3.9x10^14)= 2.58x10^-19 J
  • What is the symbol for energy?
    E
  • Electromagnetic waves with greater energy have (larger or smaller) wavelengths?
    smaller
  • What is the symbol for frequency?
    v
  • What is the speed of light?
    c = 3.00 x 10^8 m/s/s
  • What is the unit for frequency?
    Hertz (Hz or 1/s or s^-1)
  • What are valence electrons?
    electrons in the highest (outer most) energy level
  • What is the maximum number of electrons that can occupy energy level 1?
    2
  • Why does each element have a different atomic emission spectra?
    each element has a unique arrangement of electrons
  • How can you use the periodic table to determine the number of energy levels an atom has?
    look at the period (horizontal row) the element is in
  • What is the maximum number of electrons that can occupy energy level 2?
    8
  • What is the symbol for wavelength?
    λ (lambda)
  • What is the maximum number of electrons that can occupy energy level 3?
    8
  • What is the unit for wavelength?
    m