Your answer is C) The speed of sound is higher in solids than in liquids.
Answer:
A pure substance consisting only of atoms with the same number of protons in their nuclei-these appear on the periodic table
Oxygen
Hydrogen
Carbon
Sulfur
Phosphate
Nitrogen
Magnesium
Calcium
Potassium
Chlorine
(I know that these are more examples than needed, but you can use any)
Answer:
Radio waves
Explanation:
Electromagnetic waves are produced by the oscillations of electric and magnetic field. They are transverse waves, which means that the oscillations occur in a direction perpendicular to the direction of propagation of the wave, and they are the only type of waves that can travel through a vacuum.
Electromagnetic waves are classified into 7 different types, depending on their frequencies. From lowest to highest frequencies, we have:
Radio waves
Microwaves
Infrared
Visible light
Ultraviolet
X-rays
Gamma rays
Radio waves are the electromagnetic waves with lowest frequency. They are used, for examples, for satellites, telecommunication, broadcasting.
We know density = Mass / Volume
So Volume = Mass/Density
Volume = Area * Thickness

So the approximate thickness of the foil in millimeters = 
Answer:
a and b
Explanation:
Hydro static equilibrium holds a star steady and balanced. Whenever a star stops burning hydrogen in its center, there must be evolutionary improvements to maintain equilibrium for the star Of example, if a star's internal pressure and temperature fall, gravity will take over and force the star to contract and heat up, restoring stability. By contrast, if a star's internal pressure and temperature rises, the extra pressure causes the star to widen and cool, restoring balance.
so, according to above explanation options a and b both are true
a) A small increase in the star's internal pressure and temperature causes the star's outer layers to expand and cool.
b) A small decrease in the star's internal pressure and temperature causes the star's outer layers to contract and heat up.