It depends on a couple things.
Where are you? Are you writing in a hub or blog, and to whom do you write? Is it to an audience of college graduates, or a mixed group? do you have a message which is meant to reach out to everyone, or is it a professional paper that is meant to engage a few phd's on the half life of a particular isotope. All this was said to make one point: when writing or conversing, match your words to your audience.