New
New
A particle model of chemical reactions
I can draw particles diagrams of reactants and products to show how they are rearranged by a chemical reaction.
Lesson 10 of 9
New
New
- Year 8
A particle model of chemical reactions
I can draw particles diagrams of reactants and products to show how they are rearranged by a chemical reaction.
Lesson details
Key learning points
- Reactants are the chemicals that react in a chemical reaction.
- Products are the chemicals that are formed in a chemical reaction.
- The products and reactants in a chemical reaction contain exactly the same atoms.
- The atoms in the products of a chemical reaction are bonded differently to the same atoms in the reactants.
Keywords
Reactants - Reactants are the elements or compounds before a reaction takes place. Reactants are found on the left-hand side of a chemical equation.
Products - Products are the elements or compounds that are formed after a reaction has taken place. Products are found on the right-hand side of a chemical equation.
Common misconception
The idea that atoms can be created or destroyed when new products are formed.
Matter cannot be created or destroyed, only arranged differently to be formed into new products.
Use many examples of different particle diagrams to demonstrate how the number and type of atoms in the reactants are the same as in the products.
Teacher tip
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of these is true about elements?
Which of these is true about elements?
They can have variable boiling points
They are always compounds
They don't react with other elements
Q2.A metal sulfate contains the group of elements -SO₄, nitrates have the group -NO₃ and have the group -CO₃.
A metal sulfate contains the group of elements -SO₄, nitrates have the group -NO₃ and have the group -CO₃.
Q3.What elements are present in the calcium chloride?
What elements are present in the calcium chloride?
Q4.What of the following is an example of a molecular element?
What of the following is an example of a molecular element?
Si
Na
Q5.Match the reacting elements with the compound formed.
Match the reacting elements with the compound formed.
Q6.What indicates a compound in a chemical formula?
What indicates a compound in a chemical formula?
Presence of a single element
No subscripts (little numbers)
Only gases
Assessment exit quiz
6 Questions
Q1.Match the word with its definition.
Match the word with its definition.
Q2.In a chemical reaction, what happens to the atoms?
In a chemical reaction, what happens to the atoms?
New atoms are created.
Some atoms are destroyed.
Q3.In the chemical equation 2H₂ + O₂ → 2H₂O, what are the reactants?
In the chemical equation 2H₂ + O₂ → 2H₂O, what are the reactants?
H₂O
H₂ only
O₂ only
H₂O and O₂
Q4.Which of the following is a characteristic of a chemical reaction?
Which of the following is a characteristic of a chemical reaction?
Changes in state
Loss of atoms
Gain of atoms
Q5.After the reaction 2H₂ + O₂ → 2H₂O, what happens to the total number of atoms?
After the reaction 2H₂ + O₂ → 2H₂O, what happens to the total number of atoms?
It increases.
It decreases.
Not enough information is known, so it cannot be determined.
Different reaction conditions would lead to different answers.
Q6.In the equation 2Na + Cl₂ → 2NaCl, what is the simplest ratio of sodium (Na) atoms to chlorine (Cl) atoms in the reactants?
In the equation 2Na + Cl₂ → 2NaCl, what is the simplest ratio of sodium (Na) atoms to chlorine (Cl) atoms in the reactants?
2:1
1:2
2:2
3:1
