From which celestial body is a star born? A. supernova
B. nebula
C. protostar
D. black dwarf

Start an single atom tab. observe the decay of polonium-211. after each decay, press the reset nucleus button to watch the process again. write a description of alpha decay for po-211

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

How many moles are contained in 5.6 l of h2 at stp