Explanation:
when an iron bar rust is an example of a chemical change in which a new substance is formed and the change is not easily reversible.for iron to rust moisture and air must be present.while when a substance freezes,it can be easily reversed through melting and no new substance is formed.this change is termed a physical change.
Answer:
Use the formula q = m·ΔHv in which q = heat energy, m = mass, and ΔHv = heat of vaporization.
Explanation:
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Answer: Sustainable living
Explanation: It is a lifestyle by which an individual uses natural resources only as much as is necessary, which means in limited quantities, and thus reduces the general enormous exploitation of these resources. In this way, the needs of the individual are met and resources are put to use for generations to come. It also refers to personal resources as well as Earth resources in general.
It is obvious from today's point of view that if food was produced only as much as needed, it would mean not throwing away food, everyone, both those who could otherwise afford food and those who are now starving, would be fed up.
With the reduction of production not only of food but also of other necessities, that is, with production to meet the needs and not beyond, there would be less pollution and less emission of harmful hags and greenhouse effect.
Answer:
Caesium
down the group atomic radius increases and along period wise atomic radius decreases