Personalized Heart Chemical Elements Newborn Layette. A heart filled with chemical elements and their symbols is a unique chemistry design for science school teachers, students, chemists and chemical engineers. 100% combed ringspun cotton 5.8 ounce 1×1 baby rib sleeper. 3/8" flatlock binding at envelope neck and cuffs. Back sleeve flap to protect hands. Elastic opening at bottom. Infant: 0-3 Months