An experiment is designed to see if the shells of sea snails are weakened by exposure to sea water which is more acidic than normal. Shells are placed in normal sea water, sea water that is more acidic than normal, and sea water that is more basic than normal.

The shells are checked every day at 8 AM. Which of the following is the dependent variable for this experiment?

exposure to sea water that is more acidic than normal
exposure to sea water that is more basic than normal
time
the strength of the shell

wind moving at higher speeds will transfer more energy to the water, resulting in stronger waves.

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.

c. magnitude and direction

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.