I taught 4th grade for many years and in Texas that means the writing grade! My students could write about anything by the end of the year. One thing to consider...85% of what scientists do is language based. Whether it is using visual literacy to read information from a graphic, or reading or communication through writing or orally, scientists have to convey what they are thinking and questioning in a way that others will understand. They also have to understand what other scientists are saying and writing about. Science is a collaborative field full of communication. Also remember that most of what we do in the form of literacy is using technology, so use the apps/technology you might use to engage students in literacy adventures.
So in addition to reading a book and talking about/connecting the ideas in the trade book, you might try some of the following:
Interview a landform. How did it form? What is its life story? (Pairs)
Use an app such as ChatterPix to have an animal tell about its adaptations. You can use this for word banks too.
Use blogs to allow students to explain what they observed.
Use Mindomo to have students make a mindmap of an article or to generate ideas about a topic. They can share here.
Have students take digital pictures and describe what they observed in their investigations.
Write about two tools having an argument (dialogue) about who is the best tool to measure.
Have students write ways they can measure a puddle.
Have a talk show host write interview questions for the planets. Have another students write back as the planet.
Have students write a giant postcard from a landform, planet, or as a scientist telling about his/her latest discovery.
Use pictures from a unit (Animals, earth changes, etc.) to generate students' questions and ideas to explore and/ or research.
Use current events and websites like http://www.timeforkids.com/news-archive/science, or https://student.societyforscience.org/sciencenews-students to generate ideas and analyze current cutting edge science and make predictions about what these new discoveries mean for us. How will they change our lives?
Get creative. Students do not like to be bored and if you give them a choice in how they approach showing what they learned, it is a win-win for all. Have fun!