During a phase change, the temperature of a substance
a. increases
b. decreases
c. remains constant
d. may increase or decrease

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

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

The footprints of a dinosaur and the burrow of an ancient shrimp are examples of which kind of fossils