Ryan is a 13-year-old male who has just entered puberty. which change can ryan expect during this stage of his life? a thinning of body hair an increase in high-risk behaviors a more restful sleep pattern a decrease in vocal ability

The fact that the total amount of energy in a system remains constant is a(n)

What is the molecular weight of copper

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