Elements and compounds

In this topic you will recap about the differences between elements, compounds and mixtures. 

The world arround us exists because chemical reactions have created the substances we can see, touch and smell.  In this topic, you will learn how to identify physical and chemical changes. Scientists call chemical changes reactions. 

Task 2b: Make notes that:

• Draw diagrams of; an atom, element, compound and mixture.

• Define an atom, element, compound and mixture.

Task 3b: Make notes that:

• State how we know a chemical reaction has taken place.

• Define reactants and products.

• Describe what happens during a chemical reaction.

• Define the conservation of mass during a chemical reaction.

• Explain the conservation of mass during a chemical reaction.

Task 5b: Make notes that:

Based on the experiment described in the sides, answer the following:

• Give the independent variable

• Give the dependent variable

• List the control variables

• Draw a diagram of the apparatus

• Write a method for the experiment

• Use the example data in the slides (107) to plot a graph (X axis = size of beaker, Y axis = Time taken for candle to go out)

Task 6b: Make notes that:

• Describe what catalysts do.

Copy and complete the following

A catalyst is a substance that ________ ____ a chemical reaction without being ________ _____ or ________ changed.

Catalysts are usually specific to a particular _________. The best catalyst for one reaction is unlikely to have any effect at all on a different reaction. Therefore, different catalysts are needed for ___________ _______.