Answer:
an earthquake
Explanation:
the tectonic plates rub together sending shockwaves
Answer:
Lithium,Sodium,Potassium all belong to transition metals
Atomic number = amount of protons, so 7 protons.
Because it is a neutral atom, that means that the number of protons has to be the same as the number of electrons. So, there are 7 electrons.
The mass number of an atom, 15, is the total number of protons + neutrons, so 15 - 7 = 8. There are 8 neutrons
Explanation:
Whenever there occurs a decrease in the density of a substance then this is known as rarefaction.
For example, when particles of a gas become more dispersed or spread out then it means they have gained more kinetic energy. As a result, there will occur a decrease in mass of the gas and increase in volume of the gas.
As density is mass divided by volume. Hence, decrease in mass will also lead to a decrease in density of the gas.
Therefore, we can conclude that when the molecules in the air become less dense (as in the process of hearing), rarefaction has occurred.
