chemical change changes the identity of a substance, while a physical change can just be observed. Some signs that a chemical change has occurred are, <u><em>temperature change, forming bubbles, color change, new substance forming,</em></u> there are more, but those are just some of which i now
The formation of a gas is a clue to chemical changes. The bubbles of gas that you observed form when an antacid is dropped into water is an example of change. ... After ice melts into liquid water, you can refreeze it into solid ice if the temperature drops. Freezing and melting are physical changes.
Therefore, a 10x eyepiece used with a 40X objective lens, will produce a magnification of 400X. The naked eye can now view the specimen at a magnification 400 times greater and so microscopic details are revealed. More on objective lenses here. Magnification is the ability to view an object as larger.
