Why is dark matter important to study?
a. it to estimate the mass of the universe.
b. it to estimate the number of atoms in the universe.
c. it to estimate the age of the universe.
d. it to estimate the temperature of the universe.

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?

In which of the following would the particles move most rapidly? a. ice at -20 °c b. water at 20 °c c. steam at 110 °c d. boiling water e. ice at 0 °c

Which is an example of an exothermic process?