by radiation from the Earth's surface
Answer:
CH4 + 4Cl2 --> CCl4 + 4HCl
Explanation: Message me if you need a thorough explanation
Star clusters is the only thing i can think of that would apply.
Within a physical change, an element can change forms, such as going from solid to a liquid through melting. Color change can also occur during a physical change. Physical changes are very different from chemical changes. In a chemical change the element itself changes into something else within a reaction, such as combustion (burning).
Hope this helped
Answer: When a substance is pure, it is composed of one type of molecule. For example, table salt is only composed of (more or less) salt molecules, while seawater has water and salt molecules. A more complicated example of a non - pure substance is soil. It has many different types of nutrients and compounds.
