how many words in helium?

Yes there is a minimum word requirement of 400 words for a Helium article. If you try to submit an article containing fewer words it will not be accepted when you try to publish it on the site. Adding a few extra words or lines to reach the requirement should get it published successfully. A Martketplace assignment will specify a different word requirement and then you have to keep within the number of words requested by the publishers and stated in the guidelines. When I started writing at Helium over a year ago the minimum word count was 350 and sometimes I found it difficult to write even that many. Now I have more than 200 articles at Helium and I often write more than 700 words. This is not too many for Helium, but usually I cut it down to between 500 and 600 words.