PLEASE HELP ME IM CONFUSED it’s in a picture

In which layer of earth do most earthauakes occur a_ inner core b_outer core c_mantle d_crust

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?

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom