Which have scientists learned from studying seismic waves that travel through earth’s interior?

a. the outer core of earth is solid.

b. they have learned the precise depths where the boundaries between the earth's layers are located.

c. the inner core of earth is liquid.

d. earth's mantle is liquid.

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

Will give brainliest! jay rides his 2.0-kg skateboard. he is moving at speed 5.8 m/s when he pushes off the board and continues to move forward in the air at 5.4 m/s. the board now goes forward at 13 m/s.a. determine jay’s mass.b. determine the change in the internal energy of the system during this process.(express your answer to two significant figures and include the appropriate units.)

Which of the following are not typically included in the periodic table? a. atomic mass b. element symbol c. isotopes d. number of electrons