<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Thobile Nkosi</style></author><author><style face="normal" font="default" size="100%">Lindelani Mnguni</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">THE IMPACT OF PHYSICAL MOLECULAR MODELS ON STUDENTS' VISUO-SEMIOTIC REASONING SKILLS RELATED TO THE LEWIS STRUCTURE AND BALL &amp; STICK MODEL OF AMMONIA</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Baltic Science Education</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ball &amp; stick models</style></keyword><keyword><style  face="normal" font="default" size="100%">Lewis structures</style></keyword><keyword><style  face="normal" font="default" size="100%">physical models</style></keyword><keyword><style  face="normal" font="default" size="100%">visuo-semiotic reasoning</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">August/2020</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://oaji.net/articles/2020/987-1597214439.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">19</style></volume><pages><style face="normal" font="default" size="100%">Continuous</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Visuo-semiotic models, such as Lewis structures and ball &amp; stick models, are widely used to enhance students’ learning. However, there is limited research about the impact of these models on specific visuo-semiotic reasoning skills. In the current research, we aimed to determine the extent to which physical molecular models could enhance specific visuo-semiotic reasoning skills among students. The research question that we explored was, “what is the impact of physical molecular models on Grade 11 students’ visuo-semiotic reasoning skills related to Lewis structures and ball &amp; stick models of ammonia?” In this mixed-methods research, we collected data from purposively selected Grade 11 chemistry students aged between 15 and 18 from an under-resourced school in South Africa. Through a quasi-experimental design, participants in the experimental group (n = 101) used physical molecular models to learn about Lewis structure and ball &amp; stick models of ammonia while participants in the control group (n = 100) did not. We subsequently tested students' visuo-semiotic reasoning skills. Results show that using physical molecular models significantly improved students' visuo-semiotic reasoning skills and reduced associated learning difficulties. We, therefore, recommend that these models should be used as an instructional tool to enhance learning.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><work-type><style face="normal" font="default" size="100%">Original article</style></work-type><section><style face="normal" font="default" size="100%">594-604</style></section></record></records></xml>