This 'Reversible vs. Irreversible Changes' word sort activity is designed for second-grade students to align with NGSS 2-PS1-4. In this activity, students will classify different types of changes in matter as either reversible or irreversible after being heated or cooled. Items like 'ice melting' and 'bread baking' prompt students to think critically about how different materials respond to temperature changes, fostering their understanding of physical and chemical changes. Through this hands-on sorting activity, students gain insights into the effects of heating and cooling, learning that while some changes can easily be undone, others are permanent. This activity reinforces foundational concepts in matter and material science and encourages evidence-based thinking, key components of the NGSS standard.