observing change

Question 1

what is physical change

Answer 1

there is no change in the particals just the partical arrangment eg melting chocolate

Question 2

what is a chemical change

Answer 2

when a chemical reaction takes place a new substance is formed energy may be released or absorbed they are very difficult to reverse eg iron reacts with water and oxygen to form rust

Question 3

whats a chemical reaction

Answer 3

the chemicals that react together are called reactants and the substance formed is called the product

Question 4

what are signs that indicate that change has occured

Answer 4

-colour change
-temperature change
-light is emmited
-bubbles of gas are produced

Question 5

what is the law of conservation of mass

Answer 5

that mass cant be created or destroyed so there is no change in the overall mass

Question 6

what is a partical model diagram

Answer 6

shows how particals rearrange to form new substances during a reaction