1. all elements are made of small particles called atoms
2. atoms of one element are identical in their properties, different atoms from different elements differ in properties
3. chemical reactions consist of atoms rearranging in whole number ratios
4. atoms can not be subdivided, created, or destroyed
The number of chirps increases in relation to temperature.
If the ending substance has changed its properties. For example if iron rusts it is a chemical change because it is no longer the same as before it is now just rust. A physical change only changes the appearance but burning something or changing it's chemical properties is a chemical change.
