More than one process is normal for the current Firefox. http://www.ghacks.net/2016/07/22/multi-process-firefox/

Multi-process Firefox is codenamed "e10s". https://wiki.mozilla.org/Firefox/multiprocess

Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

Fred, I started in safe mode. Currently have 6 tabs open and Task manager shows 8. What should my next step be? Thank you

You can check the Firefox Task Manager (about:performance) and about:memory pages.

• https://support.mozilla.org/en-US/kb/task-manager-tabs-or-extensions-are-slowing-firefox
• https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-or-cpu-resources

It is quite normal to see more Firefox processes running.

• one process for the main Firefox thread (user interface)
• one process for the compositor thread
• one process for the WebRender when this feature is enabled
• one or more content processes, see:
  Options/Preferences -> General -> Performance
  remove checkmark: [ ] "Use recommended performance settings"
• extra privileged processes

You can find the current multi-process state on the Troubleshooting Information page (about:support).

• "Help -> Troubleshooting Information" -> "Application Basics":
  Multiprocess Windows
  Remote Processes

See also the Remote Processes section further down for more detail.