Brockton: The 20th annual Brockton Train Show will feature a variety of model and toy trains and accessories, books, photographs, and displays. Several model railroad clubs will operate large-scale model railroad layouts. Sunday, 10 a.m. to 4 p.m., Temple Beth Emunah, 479 Torrey St. $4, $3 senior citizens and ages 8 to 17, $9 family. 508-583-5810, www.templebethemunah.org.
Duxbury: The Royce Whitaker 5K Run by the Bay and Kids’ Run for Fun is a USATF-certified 5K race dedicated to the memory of Royce Whitaker, a 7-year-old Bay Farm student who died in 2009. Competitive runners, joggers, and walkers of all ages are welcomed to participate in this family-focused event. Sunday, 8:30 a.m., Bay Farm Montessori Academy, 145 Loring St. $30, $15 children. 781-383-2585, www.bfarm.org.
Norwood: Parkway Concert Orchestra presents “Water and the Sea.’’ Matthew Fritz conducts the 50-piece orchestra in a program that includes “Moldau’’ from “My Fatherland’’ by Smetana; Handel’s “Water Music Suite’’; “Russian Sailors’ Dance’’ by Gliere; and “South Pacific’’ Symphonic Scenario. The concert will feature baritone Richard Conrad. Sunday, 3 p.m., First Congregational Church, 100 Winter St. $15; $10 for seniors and students; free for children under 12 years old. 781-762-0288, www.ParkwayConcertOrchestra.org.
Event organizers: Submit items directly to boston.com/addevents.