💡 4th Grade Light & Sound Waves Unit | NGSS 4-PS3 & 4-PS4 | Hands-On Physical Science Activities Engage students with this comprehensive Light and Sound Waves Unit designed to build strong understanding of wave energy, energy transfer, vibrations, and how humans detect sound and light. With hands-on STEM activities, informational reading passages, diagrams, and response sheets — students experience science through inquiry and real-world application. Aligned to NGSS 4-PS3-2, 4-PS4-1, 4-PS