8th Science 8.5DE

Front

What is a chemical reaction?

Back

A process where substances (reactants) are transformed into different substances (products), often involving the release or absorption of energy.

Front

What evidence indicates a chemical reaction has occurred?

Back

Bubbles forming, color change, temperature change, or the formation of a precipitate.

Front

What is the chemical formula for water?

Back

H₂O, which consists of 2 hydrogen atoms and 1 oxygen atom.

Front

How do you determine the number of elements in a chemical formula?

Back

Count the different capital letters in the formula; each represents a different element.

Front

What is the significance of coefficients in a chemical equation?

Back

Coefficients indicate the number of molecules or moles of a substance involved in the reaction.

Front

What is the chemical formula for sodium sulfate?

Back

Na₂SO₄, which contains 2 sodium atoms, 1 sulfur atom, and 4 oxygen atoms.

Front

What is the difference between a compound and a mixture?

Back

A compound is a substance formed when two or more elements chemically bond, while a mixture is a combination of substances that retain their individual properties.

Front

What does balancing a chemical equation mean?

Back

Ensuring that the number of atoms for each element is the same on both sides of the equation.

Front

What is the role of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of each element in a molecule.

Front

What is an example of a chemical reaction that produces gas?

Back

The reaction between vinegar (acetic acid) and baking soda (sodium bicarbonate) produces carbon dioxide gas.