Science 10 - Week 1: Chemical Reactions

This set of flashcards covers the fundamental concepts of chemical reactions, including the differences between physical and chemical changes, the primary indicators of a reaction, and the standard symbols used in chemical equations.

Physical Change

A change that affects only the form or appearance of a substance while the composition remains the same and no new substance is formed.

Chemical Change

A process where a substance turns into one or more new substances, involving a rearrangement of atoms.

Chemical Reaction

A process where one or more substances, called reactants, change into one or more new substances, called products.

Reactants

The starting substances that undergo change during a chemical reaction.

Products

The new substances formed after a chemical reaction has occurred.

Color Change

An indicator of a chemical reaction where a new, distinct, and usually permanent color emerges that was not present in the starting materials.

Precipitate

A solid substance that forms and "falls out" when two liquids are mixed, often making the mixture cloudy or causing solids to settle at the bottom.

Gas Production

The spontaneous appearance of bubbles, fizzing, or an unexpected strong odor signifying a new gas is being formed.

Exothermic Reaction

A chemical reaction that releases heat, causing the reaction vessel to unexpectedly become hot.

Endothermic Reaction

A chemical reaction that absorbs heat, often making the reaction vessel feel cold or requiring heat from the surroundings to proceed.

$+$ (Plus Sign)

A symbol used on the left side of a chemical equation to mean "combines with" or "reacts with," and on the right side to mean "and."

Yields / Produces Arrow ($\rightarrow$)

A symbol in a chemical equation read as "produces" or "yields," separating reactants from products.

$$(s)$$

A symbol indicating that a reactant or product is in a solid state.

$$(g)$$

A symbol indicating that a reactant or product is in a gaseous state.

$$(aq)$$

A symbol for an aqueous solution, meaning the substance is dissolved in water.

$$(l)$$

A symbol representing the liquid state of matter in a chemical reaction.

Coefficients

Numbers placed in front of chemical formulas to indicate the number of molecules or moles involved, used to balance the equation.

Subscripts

Small numbers written at the lower right of an element’s symbol denoting the number of atoms of that element in the molecule.

Rusting

A chemical change where black shiny metal Iron ($Fe$) becomes dull, flaky reddish brown Hydrated Iron oxide ($Fe_{2}O_{3} \text{.} H_{2}O$).

Combustion Reaction

A type of reaction that releases energy to heat homes and move vehicles.

Oxidation-reduction Reactions

The type of reactions that keep batteries in cellphones and laptops functioning.

Ammonium chloride ($NH_{4}Cl(aq)$)

The product formed from the reaction of Ammonia ($NH_{3}(aq)$) and Hydrochloric acid ($HCl(aq)$).