A compound is a pure substance formed by the chemical combination of two or more different elements.
A compound may be splitted into simpler substances by chemical reactions, and has different properties to those of the elements that form it.
The composition of a compound is fixed: every piece of a compound has the same kind of atoms, bonded in the same way and proportion.
Some examples of compounds are H₂O, NaCl, H₂O₂, CH₃COOH. As you see, they have a chemical formula which states the kind and number of the atoms that form them.
They are different to mixtures, which are formed by two or more compounds, in a variable proportion, and can be separated by physical media. Some examples of mixtures are the solutions (e.g. NaCl dissolved in H₂O), and some solid mixtures (e.g. a mixture of marbles and sand).
<span>The answer is CFCs. The abbreviation stands for Chlorofluorocarbons. They are made by fully
halogenating paraffin hydrocarbon. These compounds are known to cause climate change damaging the ozone layer. It is,
therefore, advisable to properly dispose off of refrigerators,
solvents and propellants</span>
Melting
Melting is a change in property of matter from solid to liquid
Matter is anything that occupies space and has mass. Thus, there are fundamentally three types of matter which is solid liquid and gas. But why do gases and liquids diffuse and not solids? It is because of the molecular structure of these components of matter. If we examine the molecular structure of gas the molecules are highly scattered and liquid has also almost the same structure as mediocrely scattered that these particles can easily slip through other substances unlike solid which is entirely intact. <span> </span>
