Use everyday materials to make homemade lava lamps & experiment with liquid density, chemical bonds & acids & bases. For ages 6–12. $10–$12. Parking: $7. Two sessions: 11 a.m.–noon & 1–2 p.m. Spring Lake Regional Park Environmental Discovery Center. 393 Violetti Rd., Santa Rosa. Register 11 a.m. session: tinyurl.com/2smbff72. Register 1 p.m. session: tinyurl.com/5ew3u7wy.