Mass is the physical quantity
Answer:
Stars are at large distances that even light takes thousands of years to reach us from there.
for example, alpha centauri is 4300 light years away from earth and it is considered the nearest star to us, this means that light from there takes 4300 years to reach us and with a spaceships that can move with the speed of light is would take us 4300 years to get there which is imposible to live for that long.
hence, it is difficult to move between the stars.
This is a list of well known characteristics of acids:
1) acids increase the concentration of hydronum ions ([H3O+]) when dissolved in water
2) acids taste sour
3) many are corrosive (the higher the acidity the higher the corrosive property)
4) when acids react with some metals produce hydrogen gas
5) acids conduct electricity (due to the presence of hydronium ions)
6) acids neutralize bases
7) acids combine with bases to produce water and salt
8) acids lower the pH of solutions.
They do not feel sticky to the touch. Bases fell slippery but there is not that property of sticky sensation about acids, although some highly concentrated strong acids have high viscosity. You cannot touch highly concentrated strong acids.
Answer:
Its probably D (the sound energy)
Uhm, i'm pretty sure it's deadly.
