What is mass?
Mass is the amount of matter in an object
Is salt a pure substance or a mixture?
Pure substance
What is a heterogenous mixture?
Heterogeneous mixtures have visible components. We can see the components with the naked eye or under a microscope
What is a physical change?
Physical changes affect the properties or the state of a substance, but do not change the actual substance
What is a chemical change?
A chemical change occurs when there is a chemical reaction that changes the substance into new substances
What is volume?
Volume is the amount of space an object occupies
What are mixtures?
Mixtures are made up of two or more pure substances, called the components. Mixtures have specific properties that are different from their individual components
What is a homogeneous mixture?
Homogenous mixtures or solutions don“t have visible components
Tell me three different ways that a metal can change?
Change shape, change state and melt, rust
We digest food in order to break it down into nutrients
What are the two general properties of matter?
Mass and volume
What are the four different techniques for separating mixtures?
Filtration, evaporation, distillation, magnetic separation
Give 1 example of a heterogenous mixture
Rocks with different minerals
What is expansion?
When materials or substances increase in volume
What is combustion?
Combustion occurs when combustibles like natural gas, petrol or wood combine with a spark and oxygen and burn. The combustibles are transformed into new substances
What is density?
Density is the relationship between the mass and the volume of an object. We use a formula to calculate the density of objects
Describe the process of distillation
Distillation separates mixtures of pure substances by boiling. The evaporated substance is collected and cooled back into a liquid
Give 1 example of a homogeneous mixture
Salt water, gas mixtures, alloys
What is a deformation? Describe the two types of deformations
Deformations are changes in the shape of materials when a force is exerted on them. Deformations are temporary if the material returns to its original shape after the force is removed. Deformations are permanent if the material does not return to its orgiinal shape, for example when the object breaks
What is oxidation?
Oxidation or rusting occurs when materials like metal and copper combine with oxygen. During this process, a new substance called rust is produced
If the mass of a suitcase is 50g and the volume is 5cm cubed, what is the density?
10g/cm cubed
Describe the process of evaporation
Evaporation separates mixtures of solid and liquid solutions by boiling them until the liquid evaporates
What are alloys?
Give 1 example
Alloys are mixtures of two or more metals that are melted and mixed together. Bronze is an alloy of copper and tin
What happens to liquid mercury in a thermometer when it is heated and cooled?
When heated it increases in volume
When cooled it decreases in volume
What is fermentation? Give an example
Fermentation is the decompositon of sugars and othe substances into alcohol, carbon dioxide or lactic acid by microorganisms, like yeast.
Examples- bread dough rises, milk becomes yoghurt, grape juice becomes wine