The weather is sunny and warm after snowing. Is the snow melting a physical change or a chemical change?

When the weather becomes warm and sunny after snowing, melting of snow is a physical change. When snow melts, no new matter is produced, but the state of matter changes, so it 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. For example: changes in position, volume, shape, temperature, pressure, and mutual transformation between gaseous, liquid, and solid states, etc.

Chemical changes are changes that produce new substances. Such as iron rust, holiday fireworks, acid-base neutralization, burning of magnesium bars, etc. From a macro perspective, we can see that various chemical changes produce new substances, which is a characteristic of chemical changes. Summary: Changes caused by new substances are chemical changes. ?

Extended information:

It’s just that no new substances are generated. This is the fundamental difference between physical changes and chemical changes. According to the different types of reactants and products, chemical reactions can be divided into four basic types: combination, decomposition, substitution and metathesis.

Chemical reactions can also be classified from other perspectives, such as redox reactions and non-redox reactions. Endothermic reactions and exothermic reactions, etc. The properties of objects that appear during chemical changes are chemical properties. Chemical changes must include physical changes, and physical changes must not include chemical changes.

Common physical properties: color, state, odor, hardness, magnetism, density, melting point, boiling point, solubility, freezing point, thermal conductivity, electrical conductivity, extensibility, volatility, water absorption, whether it is soluble Yu Shui et al.

Baidu Encyclopedia-Physical Change