Classify each of these statements as always true, sometimes true, or never true.
__ST___13.In an equation, a substance is shown to be in the gaseous state by placing an upward-pointing arrow after its formula.
___ST___14. Atoms are destroyed in a chemical reaction.
___AT____15. A skeleton equation is not a balanced equation.
13. An upward arrow is used to designate a gas; (g) may also be sued. I think the statement is AT
14.Atoms are not destroyed except in radioactive decay and then they are changed to some other atom.
15. I think this one is correct if we agree on the definition of a skeleton equation.
St
St
St
What is a balanced equation when aluminum reacts with aqueous hydrochloric acid to form hydrogen gas and aqueous aluminum chloride
13. Sometimes true - An upward-pointing arrow can be used to represent a gas, but the notation (g) is more commonly used.
14. Always false - Atoms are not destroyed in a chemical reaction, they are rearranged and the total number of atoms remains the same.
15. Sometimes true - A skeleton equation is an unbalanced equation that shows the formulas of the reactants and products in a chemical reaction. However, it can be balanced to become a balanced equation.
To classify each of the statements as always true (AT), sometimes true (ST), or never true (NT), we can evaluate the accuracy of each statement:
13. In an equation, a substance is shown to be in the gaseous state by placing an upward-pointing arrow after its formula. - This statement is sometimes true (ST). An upward arrow is indeed used to designate a gas in chemical equations; however, the letter (g) may also be used to indicate a substance in the gaseous state.
14. Atoms are destroyed in a chemical reaction. - This statement is never true (NT). Atoms are not destroyed in a chemical reaction. They are rearranged and combined with other atoms to form new substances, but the total number of atoms remains the same due to the Law of Conservation of Mass.
15. A skeleton equation is not a balanced equation. - This statement is always true (AT). A skeleton equation is an unbalanced chemical equation that only shows the reactants and products without indicating the stoichiometric coefficients. To balance the equation, coefficients need to be added to ensure that the number of atoms on both sides of the equation is equal.