Fifth Grade Physical Science
We know from past grade levels that physical science is the study of the world around us. Because we are all on earth and all that we do is part of the world around us, it is argued that physical science studies encompass almost everything. It is true that everything can be a part of physical science, but generally it does not include the study of living things. It leans more towards understanding electricity, energy production, chemistry, magnetism, forensics, matter, optics, mechanics, nuclear science, acoustics, and physics. While some of these scientific studies do overlap with earth and life science, studying how they behave in the world and how it may affect us belongs to physical science.
Physical and Chemical Changes of Matter
There are two ways matter can change, physically and chemically. It is important that we understand the differences between these two types of change because they have different results. Knowing the chemical changes of matter and the consequences of that change can help us take care in the science laboratories, as well as prevent unwanted occurrences. For example, we know that some metals rust over time. Rust is a chemical change. By studying rust and how this chemical change happens, scientists have been able to create solutions that will help prevent rust or prolong its onset.
A physical change is any change in the physical state of matter. Usually these changes are caused by temperature, pressure, and motion. For example, when you apply heat to a cube of ice, it melts. The state of matter has gone through physical change, but it is still the same in terms of chemical composition, that is it is made up of hydrogen and oxygen atoms.
An example of physical change due to pressure is what happens to air when a scuba diver goes underwater. Air at atmospheric pressure behaves a certain way. However, as the diver descends deeper, the pressure builds, causing the air to become more compact inside the tank. But the components of the air inside the jar remain the same, and it is still air.
Finally, if you have a large rock by the shore of the beach, its jagged edges eventually smoothen out because of the constant coming and going of the waves. This is a physical change caused by motion.
Chemical changes are changes in the molecular structure of the matter. This means that these changes happen on a much smaller scale and it can take a while before the change is even noticed (like the rusty metals.) These changes are often caused by chemical reactions that matter undergoes when it mixes with certain substances. On the molecular level, the matter undergoes several changes and usually ends up with a different molecular structure. This substance is new and wasn't part of the original matter. Sometimes more than one new substance is produced in a chemical change. We can note some of these changes by watching out for heat or light being emitted, bubbles or gas being formed (a common bi‐product in chemical reactions), a change in smell, or a change in color.
Next Article: Tracking Physical and Chemical Change
