old_contents: from bokeh.plotting import *
  from bokeh.sampledata import periodic_table
  
  elements = periodic_table.elements
  elements = elements[elements['atomic number'] <= 82]
  elements = elements[~pd.isnull(elements['melting point'])]
  mass = [float(x.strip('[]')) for x in elements['atomic mass']]
  elements['atomic mass'] = mass
  
  palette = list(reversed([
      '#67001f','#b2182b','#d6604d','#f4a582','#fddbc7','#f7f7f7','#d1e5f0','#92c5de','#4393c3','#2166ac','#053061'
  ]))
  
  melting_points = elements['melting point']
  low = min(melting_points)
  high= max(melting_points)
  melting_point_inds = [int(10*(x-low)/(high-low)) for x in melting_points] #gives items in colors a value from 0-10
  meltingpointcolors = [palette[i] for i in melting_point_inds]
  
  output_server("elements")
  
  hold()
  
  circle(elements['atomic mass'], elements['density'] ,
         color=meltingpointcolors, plot_width=1200, line_color='black',fill_alpha=0.8,
         size=12, title='Density vs Atomic Weight of Elements (colored by melting point)',
         background_fill= '#cccccc', tools='pan, wheel_zoom, box_zoom, reset')
  
  text(elements['atomic mass'], elements['density'] +0.3,
      text=elements['symbol'],angle=0, text_color='#333333',
      text_align="center", text_font_size="10pt")
  
  xaxis().axis_label='atomic weight (amu)'
  yaxis().axis_label='density (g/cm^3)'
  grid().grid_line_color='white'
  
  show()
  
new_contents: import pandas as pd
  
  from bokeh.plotting import *
  from bokeh.sampledata import periodic_table
  
  elements = periodic_table.elements
  elements = elements[elements['atomic number'] <= 82]
  elements = elements[~pd.isnull(elements['melting point'])]
  mass = [float(x.strip('[]')) for x in elements['atomic mass']]
  elements['atomic mass'] = mass
  
  palette = list(reversed([
      '#67001f','#b2182b','#d6604d','#f4a582','#fddbc7','#f7f7f7','#d1e5f0','#92c5de','#4393c3','#2166ac','#053061'
  ]))
  
  melting_points = elements['melting point']
  low = min(melting_points)
  high= max(melting_points)
  melting_point_inds = [int(10*(x-low)/(high-low)) for x in melting_points] #gives items in colors a value from 0-10
  meltingpointcolors = [palette[i] for i in melting_point_inds]
  
  output_server("elements")
  
  hold()
  
  circle(elements['atomic mass'], elements['density'] ,
         color=meltingpointcolors, plot_width=1200, line_color='black',fill_alpha=0.8,
         size=12, title='Density vs Atomic Weight of Elements (colored by melting point)',
         background_fill= '#cccccc', tools='pan, wheel_zoom, box_zoom, reset')
  
  text(elements['atomic mass'], elements['density'] +0.3,
      text=elements['symbol'],angle=0, text_color='#333333',
      text_align="center", text_font_size="10pt")
  
  xaxis().axis_label='atomic weight (amu)'
  yaxis().axis_label='density (g/cm^3)'
  grid().grid_line_color='white'
  
  show()
  
subject: Add missing pandas import to plotting/server/elements.py