A model of (CH,0), was created using colored beads. Carbon atoms were represented by black beads, hydrogen atoms by red beads, and oxygen atoms by blue beads. Which of the following combinations of beads shows an accurate model of (CH,0)4?
A.) 4 black, 8 red, and 4 blue
B.) 1 black, 2 red, and 1 blue
C.) 4 black, 6 red, and 4 blue
D.) 1 black, 8 red, and 1 blue

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