Chemical Equations, Balancing, and Reaction Types

Vocabulary flashcards covering chemical equations, the law of conservation of matter, subscripts, coefficients, and endothermic versus exothermic reactions.

Law of Conservation of Matter

A fundamental scientific law stating that matter is neither created nor destroyed, but can be transferred, rearranged, or stored, meaning that elements and their quantities are neither lost nor gained during a chemical reaction.

Chemical Equation

A symbolic representation of a chemical process consisting of three distinct parts: reactants, yields, and products.

Reactants

The elements and/or compounds that the chemical reaction is affecting, positioned opposite to where the yields arrow points.

Yields

The arrow ($\rightarrow$) in a chemical equation that indicates a chemical reaction is taking place and points toward the products.

Products

The substances resulting from a chemical reaction, showing how the elements and/or compounds have been rearranged.

Subscript

A small number placed to the lower right of a chemical symbol (such as the $2$ in $N_2$) that indicates how many atoms of that specific element are present.

Subscripts Around Parentheses

A notation rule indicating that all elements enclosed within the parentheses must be multiplied by the subscript placed directly outside them (for example, in $(OH)_2$).

Coefficient

A number placed in front of a chemical formula (such as the $2$ in $2H_2O$) that multiplies all elements in that specific part of the equation.

Simplest Form

The required state of a balanced chemical equation in which the coefficients cannot be mathematically reduced any further.

Endothermic

A chemical reaction or process in which heat is absorbed (taken in) by the system from the surroundings, where energy or heat acts as a reactant.

Exothermic

A chemical reaction or process in which heat is released into the surroundings, resulting in energy as a product and feeling hot to the touch.

Sugar (Chemical Formula)

Identified by the chemical formula $C_{12}H_{22}O_{11}$, which decomposes into carbon ($C$) and water ($H_2O$) when burned.