Chemical Formulas, Equations, and Reactions

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What is a chemical formula?

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A chemical formula is a way of expressing the composition of a substance using symbols for its constituent elements and numbers to indicate the ratio of atoms.

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What does a balanced chemical equation represent?

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A balanced chemical equation represents a chemical reaction where the number of atoms of each element is the same on both sides, adhering to the Law of Conservation of Mass.

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What is the Law of Conservation of Mass?

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The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

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How do you determine if a chemical equation is balanced?

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To determine if a chemical equation is balanced, count the number of atoms of each element on both sides of the equation and ensure they are equal.

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What is the coefficient in a chemical equation?

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A coefficient is a number placed in front of a chemical formula in an equation to indicate how many molecules or moles of that substance are involved in the reaction.

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How many atoms of oxygen are in H2O?

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There are 1 atom of oxygen in H2O.

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What is the significance of subscripts in a chemical formula?

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Subscripts indicate the number of atoms of each element in a molecule; for example, in H2O, the '2' indicates there are 2 hydrogen atoms.

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What is the product of the reaction between sodium (Na) and water (H2O)?

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The products of the reaction between sodium and water are sodium hydroxide (NaOH) and hydrogen gas (H2).

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How many aluminum atoms are in Al2O3?

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There are 2 aluminum atoms in Al2O3.

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What does it mean for a reaction to be exothermic?

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An exothermic reaction is a chemical reaction that releases energy in the form of heat or light.