Starter quiz
- Which of these is true about elements?
- They can have variable boiling points
- They are organised in the Periodic Table ✓
- They are always compounds
- They don't react with other elements
-
- A metal sulfate contains the group of elements -SO₄, nitrates have the group -NO₃ and ______ have the group -CO₃.
- 'carbonates' ✓
- What elements are present in the calcium chloride?
- 'calcium and chlorine' ✓
- What of the following is an example of a molecular element?
- Si
- O₂ ✓
- Na
-
- Match the reacting elements with the compound formed.
- copper + oxygen⇔copper oxide ✓
- copper + sulfur + oxygen⇔copper sulfate ✓
- potassium + bromine⇔potassium bromide ✓
- potassium + bromine + oxygen⇔potassium bromate ✓
- zinc + carbon⇔zinc carbide ✓
- zinc + carbon + oxygen⇔zinc carbonate ✓
- What indicates a compound in a chemical formula?
- Presence of a single element
- No subscripts (little numbers)
- Multiple different elemental symbols ✓
- Only gases
-
Exit quiz
- Match the word with its definition.
- Reactants⇔substances present before a chemical reaction has taken place. ✓
- Products⇔substances formed after a chemical reaction has taken place. ✓
- In a chemical reaction, what happens to the atoms?
- New atoms are created.
- Some atoms are destroyed.
- They are rearranged. ✓
-
- In the chemical equation 2H₂ + O₂ → 2H₂O, what are the reactants?
- H₂O
- H₂ and O₂ ✓
- H₂ only
- O₂ only
- H₂O and O₂
-
- Which of the following is a characteristic of a chemical reaction?
- Changes in state
- Loss of atoms
- formation of new substances ✓
- Gain of atoms
-
- After the reaction 2H₂ + O₂ → 2H₂O, what happens to the total number of atoms?
- It increases.
- It decreases.
- It remains the same. ✓
- Not enough information is known, so it cannot be determined.
- Different reaction conditions would lead to different answers.
-
- In the equation 2Na + Cl₂ → 2NaCl, what is the simplest ratio of sodium (Na) atoms to chlorine (Cl) atoms in the reactants?
- 1:1 ✓
- 2:1
- 1:2
- 2:2
- 3:1
-
Worksheet
Loading worksheet ...
Presentation
Loading presentation ...
Video
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.
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.
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.
+