5. How many moles are present in 4.20x10^24 atoms of Pb

Different isotopes indicate that an element will have different numbers of

What is the number of moles in 15.0 g ash3?

The twister and runaway train are two coasters at the same amusement park. both coasters start at the same height. the coaster for the twister is twice the mass of the coaster for the runaway train. which roller coaster has greater gravitational potential energy at the start of the ride?