Which one of the following substances can be separated into several different elements?

A: Air

B: Iron

C: hydrogen

D: nickel

What methods of charging does John use? John charges the rod through induction, then charges the electroscope through friction. John charges the rod through conduction, then charges the electroscope through induction.

If the fuel he carries produces 36 kJ of heat per gram when it burns, how much fuel should he carry? (For the sake of simplicity, assume that the transfer of heat is 100 %% efficient.)

A sensor is used to monitor the performance of a nuclear reactor. The sensor accu-rately reflects the state of the reactor with a probability of. 97. But with a probabilityof.

A rod of mass M and length L can rotate about a hinge at its left end and is initially at rest. A putty ball of mass m, moving with speed V, strikes the rod at angle θ from the normal and sticks to the rod after the collision.

An element's atomic number is 34. How many protons would an atom of this element have?

A block of mass 1.3 kg is resting at the base of a frictionless ramp. A bullet of mass 50 g is traveling parallel to the ramp surface at 250 m/s. It collides with the block, enters it, and exits the other side at 100 m/s.

Metals are good thermal conductors - that is, when there is a temperature difference across their ends, they transfer energy very efficiently from the higher temperature end to the lower temperature end.

Some stars are so far away that their light hasn't reached Earth yet. A million years in the future, will the sources of light we see when we look up at night be the same? Why or Why not?

A sound wave travels through water. What best describes the direction of the water particles?

After heavy rains, the floodplain of a river can deposit sediment. The newly deposited soil is nutrient rich and would be good A. to use in a construction area. B. for growing vegetation and crops. C. for holding objects in the ground. D.