Describe how you would find out whether copper(ii) oxide was a catalyst for the decomposition of hydrogen peroxide solution. You need to show not only that it speeds the reaction up, but that it is chemically unchanged at the end.​

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt

Match each statement with the state of matter it describes