There are many ways. For example, only reading text perhaps from a publishers textbook written at an elementary grade reading level. This might also be followed by "end of the Chapter" questions correctly answered by re-reading the chapter or guessing or leaving the answer to the question BLANK.
Another way might be merely "lecturing" to the children again thereafter, assigning the end of chapter questions and/or "workbook" pages. The lecture would be written by the classroom teacher or written by a publisher, perchance, read to the class by the teacher as scripted.
Teaching Science with elementary aged children could have as many "ways" as there are circles and geometric shapes above.
Is there only one way to teach science with elementary aged children? Repeatedly, no.
The Next Generation Science Standards [NGSS] states:
The Next Generation Science Standards (NGSS) are K–12 science content standards. Standards set the expectations for what students should know and be able to do. The NGSS were developed by states to improve science education for all students.A goal for developing the NGSS was to create a set of research-based, up-to-date K–12 science standards. These standards give local educators the flexibility to design classroom learning experiences that stimulate students’ interests in science and prepares them for college, careers, and citizenship. [http://www.nextgenscience.org/]