Slash and Burn
What is it?
An agricultural method where trees are cut down and burned to clear plots of forest land.
What is Dissolving?
A mixture of two solids can be separated by using a solvent which dissolves only one of them.
Name 3 States of matter
Gas
Solid
Liquid
What is a Mixture?
One that contains two or more different substances that are not chemically combined together.
Why?
To make land available for growing crops, especially in places where open land for farming is not available due to thick vegetation.
Give 1 example of Dissolving
A mixture of salt and sand can be separated by adding water to the mixture. Salt will dissolve in water but sand will not.
We can obtain sand by filtration of the mixture and salt from evaporation of the filtrate.
What is a Solute?
Give 1 example
Dissolved in the solvent.
Ex: salt
What is a Solution?
Solute and Solvent
What are the 3 steps?
1) Trees are cut down to clear the land and left to dry.
2) Burning
3) New crops are planted
Give 1 Home application (example) of Dissolving a solute
(a) Cooking of soup
(b) Drinks sweetener
(c) Cleaning of the household
What is a Solvent?
Give 1 example
Water
Food is usually a mixture of A and B
Solids and Liquids
4 Disadvantages
(a) Haze, which causes:
(i) Poor visibility
(ii) Breathing difficulties and eye irritation
(iii) Higher air temperature
(b) Soil erosion
(c) Possible spread of forest fires
(d) Loss of natural habitats and extinction of
species
Carbon dioxide gas is dissolved in Coca- Cola to create the “fizzy” effect which improves the taste of the drink.
What are the:
Solute, Solvent, Purpose
Solute: Carbon dioxide gas
Solvent: Coca- Cola
Purpose: "fizzy" effect
Name 5 Separation Techniques
(a) Dissolving
(b) Filtration
(c) Evaporation
(d) Distillation
(e) Paper chromatography
Give 1 example of a Mixture of Food
Orange juice is made up of orange pulps, sugars, water and many other substances including Vitamin C.