Personalized Heart Elements Toddler T-Shirt. A heart filled with Chemical Elements and their symbols is a unique chemistry design for students, teachers, chemists and chemical engineers. A toddler-soft cotton tee in look-at-me, big kid colors. 4.5 oz., 100% combed ringspun cotton. White is sewn with 100% cotton thread. Topstitched rib crew neck. Double-needle stitched sleeves and bottom hem. Shoulder-to-shoulder taping.