Answer:
Explanation:
1. New substances such as carbondioxide and water is formed.
2. There is evolution of gas bubbles. Gases are released.
3. There is either the absorption of energy or release of energy in form of light and energy.
4. The reaction is irreversible i.e it cannot be reversed, it is permanent once the reaction take place.
5. There is a change in both odor and smell.
A chemical change is a change where new substances are formed due to changes in the properties.
They have the same number of electrons in their outer shells. Elements in the same group often share similar chemical properties because the outer electrons generally determine a lot of their properties
They flow through the inslation of the house .
they both help things travel
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.
