Scientists primary form of communication is through writing. Claim, Evidence and Reasoning standards are part of the 21st Century NGSS Standard . The first problem with reluctant writers is getting started. Here is a worksheet to jump start the process!
I use with Writing Wednesday activities when we are closing a content topic.
Have students start with "brain dumping" all of their knowledge onto the page...then organize the braindump following the - this leads naturally into a draft format to elaborate on ideas.