Mae'r pynciau yn y llyfr hwn yn helpu disgyblion i ddeall nodweddion defnyddiau drwy ymchwiliad. Maent yn atgyfnerthu dulliau ymchwil gwyddonol trwy fynnu bod disgyblion yn cynllunio ac yn gwneud gweithgareddau ymarferol, ystyried tystiolaeth, a chyfl wyno syniadau a chasgliadau. Mae nhw'n canolbwyntio ar greu grwpiau a dosbarthu defnyddiau, newid defnyddiau a gwahanu cymysgedd o ddefnyddiau, ond mae hefyd yn cynnwys cysyniadau eraill fel grymoedd, gwres a magneteg yng nghyswllt deall nodweddion defnyddiau. The topics in this book help pupils understand the properties of materials through investigation. They reinforce methods of scientific enquiry by requiring pupils to plan, carry out practical activities, consider evidence, and present ideas and conclusions. They focus on grouping and classifying materials, changing materials, and separating mixtures of materials, but other concepts such as forces, heat and magnetism are also included within the context of understanding the properties of materials. The three books in the Brilliant Support Activities Science series are an ideal way of introducing scientific terms in Welsh. The books are designed to develop the essential skills of observation, predicting, recording and drawing conclusions. The books contain a mixture of paper-based tasks and 'hands on' activities. The reproducible worksheets introduce one concept or statement per sheet (unless they are review sheets), and they can be used in any order. They are designed for use by individual pupils or to be used as a class activity if all the class are working at the same ability range.