Sound waves are longitudinal waves that is, are transmitted in the same direction of oscillation of the particles in the medium. Electromagnetic waves are transverse ie, the electric and magnetic fields, which are perpendicular to each other, oscillate perpendicularly to the direction of wave propagation.
Explanation:
It is known that formula for the ionization energy of hydrogen atom is as follows.
E = 
or, n = 
The value of energy is given as 0.544 eV. Therefore, we will calculate the value of n as follows.
n =
= 
= 5
Thus, we can conclude that n equals to 5 for a hydrogen atom if 0.544 eV of energy can ionize it.
Answer:
I think its B im not sure
but i hope this helps
Earth contains huge quantities of water in its oceans, lakes, rivers, the atmosphere, and believe it or not, in the rocks of the inner Earth. Over millions of years, much of this water is recycled between the inner Earth, the oceans and rivers, and the atmosphere. This cycling process means that freshwater is constantly made available to Earth's surface where we all live. Our planet is also very efficient at keeping this water. Water, as a vapor in our atmosphere, could potentially escape into space from Earth. But the water doesn't escape because certain regions of the atmosphere are extremely cold. (At an altitude of 15 kilometers, for example, the temperature of the atmosphere is as low as -60° Celsius!) At this frigid temperature, water forms solid crystals that fall back to Earth's surface.
Many people live faraway from freshwater sources. They need to carry their water home.
While our planet as a whole may never run out of water, it's important to remember that clean freshwater is not always available where and when humans need it. In fact, half of the world's freshwater can be found in only six countries. More than a billion people live without enough safe, clean water.
Also, every drop of water that we use continues through the water cycle. Stuff we put down the drain ends up in someone or something else's water. We can help protect the quality of our planet's freshwater by using it more wisely.
The columns of the periodic table, also referred to as "groups" contain elements with similar reactive properties, due to these elements having a similar configuration of electrons in their outer shell.
