Conservation of mass and balanced symbol equations

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Waxaan sharxi karaa ilaalinta cufka oo aan u qori karaa isla'egyo kiimikaad oo dheeli tiran si aan u muujiyo sida atomada falceliyeyaasha falcelin kiimikaad loo habeeyo si ay u sameeyaan waxsoosaar.

Introduction

In this lesson: I can explain the conservation of mass and write balanced chemical equations to show how the atoms of reactants in a chemical reaction are rearranged to form products. The mass of the products in a chemical reaction is the same as the mass of the reactants. Word equations are a simple way of describing chemical reactions.

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The mass of the products in a chemical reaction is the same as the mass of the reactants. Word equations are a simple way of describing chemical reactions. Chemical formulae represent the numbers of each type of atoms in a reactant or product. Chemical equations represent how the atoms in the reactants rearrange to form the products. The arrow in a chemical equation represents the words ‘changes into’.

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Quizzes

1. What is a molecule?
- A single atom of an element.
- Correct answer:Two or more atoms chemically bonded together.
- A mixture of different compounds.
- A type of chemical reaction.
2. Which of the following is a compound?
- O₂
- Correct answer:H₂O
- N₂
- He
3. What happens to atoms during a chemical reaction?
- They disappear.
- They are created from nothing.
- Correct answer:They rearrange to form new substances.
- They stay the same and do not change.
4. What is the chemical formula for carbon dioxide?
- CO
- Correct answer:CO₂
- C₂O
- C₂O₂

1. What does the arrow in a chemical equation represent?
- equal to
- plus
- Correct answer:changes into
- multiplies
2. Which of the following statements about the mass of reactants and products in a chemical reaction is correct?
- The mass of the reactants is greater than the mass of the products.
- The mass of the reactants is less than the mass of the products.
- Correct answer:The mass of the reactants is equal to the mass of the products.
- The mass of the reactants can be greater or less than the mass of the products.
3. What is a word equation?
- A way of describing a reaction using symbols.
- Correct answer:A way of describing a reaction using chemical names of reactants and products.
- A balanced symbol equation.
- A type of chemical formula.
4. Why must symbol equations be balanced?
- To change the identity of the reactants.
- To show that matter is created or destroyed.
- Correct answer:To correctly represent the conservation of mass.
- To make the equation more complicated.

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