The molecules in this substance are packed tightly and vibrating. the substance might be

Aball tossed vertically upward from the ground next to a building passes the bottom of a window 1.8 s after being tossed and passes the top of the window 0.20 s later. the window is 2.0 m high from top to bottom. what was the ball's initial velocity? the unit vector j^ is directed upward. how far is the bottom of the window from the launch position? how high does the ball rise above the launch position?

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

Which of the following could represent a single-replacement reaction? a. element + compound = element + compound b. element + element = compound c. compound +compound = compound + compound d. compound = element + element