6.4*10^10 is the answer in scientific notation
True
sound travels as energy, unlike light.. the waves transmit energy by changing the motion of particles. The particles are moving in the same direction as the wave.
Magnesium oxide is the metallic oxide which dissolve in water
-use headphones
-do not take up extra seats/space using their luggage or bags
-be aware of their surrounding so they do not bump into people or step on their feet
