Which atoms above have an atomic mass that are twice their atomic mass that are twice their atomic number?

a) hydrogen, carbon, nitrogen

b)oxygen, fluorine, sodium

c)aluminum, sulfur, chlorine

d)helium, nitrogen, sodium

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

As a pendulum bob swings back and forth several times, the maximum height it reaches becomes less and less. this is because more and more of the pendulum bob's energy is being transformed into a. heat energy b. kinetic energy c. potential energy d. kinetic energy and potential energy

Suppose a soccer ball is kicked from the ground at an angle 20.0º above the horizontal at 8.00 m/s. the y-velocity is determined to be 2.74 m/s. how long will the ball be in the air? assume the ball lands at the same height at which it was kicked.