Chemical Reactions

What is a chemical reaction? Think, pair, share. Think quietly then discuss with your neighbour what you think a chemical reaction is. Be prepared to share your answer.

What is a chemical reaction? “ a chemical reaction occurs when two or more chemicals join together to form a new substance”

Chemical Reactions Think, pair, share. Can you think of any chemical reactions that you have come across already in Science? Be prepared to share your answer

Chemical reactions – What to look for There may be a change of colour

Chemical reactions – What to look for There may be a gas given off (bubbles)

Chemical reactions – What to look for There may be an energy change – temperature increases or decreases

How do we know a chemical reaction is happening? Some or all of the below things can happen during a chemical reaction as new substances are formed:- Change of colour Change of temperature (up or down) Bubbles of gas maybe produced (effervescence)

Class Practical For each of the experiments you are going to carry out, you need to record your observations, then decide if a chemical reaction is happening.

Class Practical Experiment Observations Experiment 1 Magnesium + Oxygen Experiment 2 Sodium carbonate Hydrochloric acid Experiment 3 Sodium hydroxide Experiment 4 Hydrochloric Acid Experiment 5 Ethanoic acid Potassium Iodide Lead nitrate

Task  Investigating chemical reactions Record your observations on the worksheet Complete the word and symbol equations Extension: Balance the symbol equations