Science exercise grade six
Sure! Here is a science exercise for a sixth-grade student:
Question: What is the difference between a physical change and a chemical change?
Answer: A physical change is a change in the size, shape, or state of matter, where the substance remains the same. For example, when water freezes into ice, it is still water and can be melted back into its liquid form. On the other hand, a chemical change is a change in which a new substance is formed. This change involves the breaking and forming of chemical bonds. For example, when iron rusts, it reacts with oxygen in the air to form a new substance called iron oxide. The rusted iron cannot be easily converted back to its original form.
Now, here are three statements. Determine if each describes a physical change or a chemical change:
1. Cutting a piece of paper in half.
2. Burning a piece of wood.
3. Folding a piece of paper into a paper airplane.
Answers:
1. Cutting a piece of paper in half - Physical change: The paper remains the same substance, but its shape has changed.
2. Burning a piece of wood - Chemical change: The wood reacts with oxygen, releasing energy and creating new substances like ash and smoke.
3. Folding a piece of paper into a paper airplane - Physical change: The paper remains the same substance, and its shape changes, but no new substances are formed.
Hope this exercise helps!