The Nebraska Center for Materials and Nanoscience will give a sample of STEM/Nano related topics that their trained undergraduate outreach assistants, who are Physics/Chemistry/Engineering students, are available to present to K-12 classrooms. These 1 hour lessons cover a large variety of science subjects, from DNA to space travel and can be customized to the curriculum needs of each teacher. Basic information about some of the lessons can be seen at
https://ncmn.unl.edu/teacher-resources#tab3.