Physical and Chemical Changes (Q&A (Q: Is fizzing a chemical change or…
Physical and Chemical Changes
A physical change affects the form of something, but not chemically. It does not create a new substance, everything just stays the same.
A physical change can be undone.
An example of physical change, is making clothes. you cut and sew the pieces of cloth together, and it turns into a shirt. But it is still cloth. It just looks different, but it hasn't gone through a chemical change.
Another example of physical change, is water. It can turn into ice and gas. But ice can be turned into water, it melts; water can be turned into ice, it freezes; water can turn into gas, it's heated; gas can turn into water, it condenses. It doesn't change into a different substance.
Another physical change, is when sugar dissolves in water. The sugar and water can still be separated. Sugar and water does not create a new substance.
When you mix butter, sugar, flour and eggs, it is still a physical change. It isn't easy to separate those ingredients, but it is only a physical change.
A physical change may change its state of matter, shape and size.
Chemical changes can occur when the particles of 2 substances create a new substance.
A chemical change cannot be undone.
An example of chemical change, is when you bake something. you put it in the oven, and the temperature inside the oven gets hotter, and the mixture then goes through a chemical change, gases are released, and makes the mixture rise and turns into delicious baked goods.
Another example of chemical change, is when you burn wood, it doesn't stay as wood - it turns into ashes, which is a new substance. The wood can change colour, release gas, smoke, and produce odour.
A chemical change must form a new substance.
Chemical indicators: Bubbles, fizzing, temperature change, colour change.
Q: Is fizzing a chemical change or physical change?
Q: Is physical change just changes that happen in front of your eyes?
A: Not necessarily. Baking happens in front of your eyes, but it is a chemical change.
Q: Cake can't be unbaked, right? Therefore would it be a chemical change?