Correct answer only ! ian walks 2 km to his best friend’s house, then walks 0.5 km to the library. he then makes a 2.5 km walk home. the entire walk took him 3 hours. what is his average speed in km/h? show your work!

How many molecules are present in 3 mols of silicon dioxide (sio2)?

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 of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.