Answer:
Option C= light is emitted as electron falls from the excited state to the ground state releasing a photon.
Explanation:
Electrons are responsible for the production of colored light.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10⁻³¹ Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
How electrons produce the colored light:
Excitation:
When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits.
De-excitation:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum.
The best answer is:
a. Extrusive igneous rocks
In general, rocks that are formed by the cooling of magma are classified as igneous rocks. The key word however in this case is "lava," which is magma that reached the surface. This is what makes it an extrusive igneous rock, because it formed in the surface.
Answer:
The correct option is;
Group 12
Explanation:
A metallic element that is shiny and silver colored that can exist in the +1 and +2 ionic states and which forms a bright red compound with sulfur is mercury, Hg
The compound formed between mercury and silver is one of the earliest synthetic compound also known as vermilion and cinnabar. The bright red pigment of the HgS is used widely and is one of the most favorite pigment found in medieval European outstanding works of arts and in Chinese decorated wares made of lacquer as well as in mesoAmerica.
Answer:
The history of water supply and sanitation is one of a logistical challenge to provide clean water and sanitation systems since the dawn of civilization. Where water resources, infrastructure or sanitation systems were insufficient, diseases spread and people fell sick or died prematurely.
Explanation:
