Properties and Changes of Materials - Scientific investigations
Throughout the Autumn term, Year 5 have been conducting a variety of scientific investigations as part of their topic, Properties and Changes of Materials.
To begin the topic, the children planned and conducted experiments around dissolving. This quickly led them to the conclusion that some materials dissolve, while other materials do not. Through testing a range of solids (flour, sugar, bath salts, baking powder, talcum powder and salt), the children concluded that when a material dissolves, it breaks down in the liquid and cannot be seen. However, if it is not soluble it remains separate and can be seen. The speed of dissolving is affected by the temperature of the liquid; the warmer the liquid the more energy it has to dissolve the solid, as shown by our experiments.
Next, the children investigated different ways to separate materials including sieving, filtration, magnetism, evaporation and by hand. This experiment required advanced planning and the children considered the best order and equipment to use to separate their materials.
After this, the children were tasked with investigating which changes to materials were reversible, and which were irreversible. When cooking (and burning!) bread, some of the original material was lost during the change, and a new material was formed. Therefore, it was clear that this was an irreversible chemical reaction. The children enjoyed the long-lasting aroma of toast in the classroom whilst drawing their scientific conclusions.
Finally, a further irreversible chemical reaction was seen when mixing bicarbonate of soda and vinegar. This was shown through an immediate reaction, where carbon dioxide was released, changes in colour and strong smell produced. The children predicted these irreversible changes, which proved to be accurate.
The children added to their knowledge of materials and the changes that can take place when researching different scientists that uses irreversible changes to create new materials, that can be used for different purposes. For example, Spencer Silver and his accidental invention of the Post It note.
