Periodic table of the elements
gem install theelementsgit clone https://github.com/nimacpp/elements
cd elements
gem build theelements.gemspec
gem install theelements*.gemin terminal
$ elements
and in ruby
irb(main):001> require "theelements"
=> true
irb(main):002> a = Elements.new()
=> #<Elements:0x000072594ed2d1f0>
irb(main):003> a.list()["H"]
=> {:name=>"Hydrogen", :atomic_number=>1}
irb(main):004>