This study focuses on facilitation for enrichment of beginner Physical Sciences teachers to utilise Problem-Based Learning (PBL) while teaching the topic - Particulate Nature of Matter (PNM) which might enhance skills such as collaboration, critical-thinking, creativity, and communication. The problem is that there is a gap between training of science teachers and the real practice. Beginner teachers are not fully equipped with the necessary pedagogic skills that compromises their teaching practices. The purpose of this study is to enhance the utilisation of PBL by beginner Physical Sciences teachers in the teaching of PNM through a Teacher Professional Development (TPD) training. This study contributes to research related to improving Physical Sciences beginner teachers’ use of PBL. Social interdependence theory was adopted as the theoretical framework that underpins this research study, specifically focusing on shared influence between individuals in a small group. This study engaged with PBL-21st- century skills-development conceptual framework, adopting in the process a qualitative case study approach that is exploratory. This qualitative study was conducted within an interpretivist paradigm, allowing the researcher to view the world through the perceptions and experiences of the beginner teacher participants. Data was generated by means of an open-ended questionnaire, portfolio and interviews. This study employed purposive sampling, leading on to the snowballing technique and 5 participants were selected. Data was analysed using Saldaña's (2009) analytical framework, Golightly’s (2013) and Family Secret’s (2009) rubrics for learners’ activities. The overall portfolio data was analysed using an adapted Smith et al.’s (2001) analytic tool. This study’s findings show that TPD enhances beginner teachers’ knowledge and implementation of PBL; before the TPD programme, beginner teachers had limited knowledge on PBL; post the TPD programme, the extent of utilisation of PBL in initiating and promoting the 21st-century skills was highly satisfactory; there are four PBL principles of practice which could be distilled. This study demonstrates that PBL can be effectively implemented in Chemistry education. With relevant 21st-century skills gained through PBL, the study established that this might in turn lead to Self-Directed Learning (SDL). This study recommends that beginner teachers who participated in this study continue to implement PBL every year in the teaching of Grade 10 PNM and related topics since they are fully conversant with the approach and have PBL skills and tasks they could gainfully deploy. This study should be adapted and extended to other science subject areas.