It's sunny and warm after the snow. Is snow melting a physical change or a chemical change?

It is sunny and warm like spring after snow, and the melting of snow is a physical change. When snow melts, no new matter is produced, but the state of matter has changed, so this is a physical change. ?

Physical change means that although the state of a substance has changed, generally speaking, the composition of the substance itself has not changed. Such as the change of position, volume, shape, temperature and pressure, and the transformation between gas, liquid and solid.

Chemical change is a change that produces new substances. Such as rust, holiday fireworks, acid-base neutralization, magnesium rod burning and so on. Macroscopically, we can see that all kinds of chemical changes have produced new substances, which is the characteristic of chemical changes. Summary: Changes caused by new substances are chemical changes. ?

Extended data:

Only no new substance is produced, which is the fundamental difference between physical change and chemical change. According to the different kinds of reactants and products, chemical reactions can be divided into four basic types: combination, decomposition, substitution and double decomposition.

Chemical reactions can also be classified from other angles, such as redox reactions and non-redox reactions. Endothermic reaction and exothermic reaction, etc. The properties of an object in chemical changes are chemical properties. Chemical changes must have physical changes, and physical changes must have no chemical changes.

Common physical properties: color, state, smell, hardness, magnetism, density, melting point, boiling point, solubility, freezing point, thermal conductivity, electrical conductivity, ductility, volatility, water absorption, water solubility, etc.

Baidu Encyclopedia-Physical Changes