The term "pericardiocentesis" means:

select one:

a. narrowing of the arteries supplying the heart.

b. surgical repair of the sac around the heart.

c. the removal of fluid from around the heart.

d. a surgical opening made in the heart.

Option (C)

Explanation:

'Pericardiocentesis' is a biological term that is usually defined as a process by which a fluid is removed from the sac that is oriented around the heart. This accumulation of fluid in the heart is commonly known as pericardial effusion. This process is mainly carried out with the help of a needle and a catheter, where the needle is injected into the tissues that are near to the heart.

This fluid that is eliminated from the body is further sent to the laboratories in order to carry out the medical test to determine if a person is affected by infection or cancer.

Thus, the correct answer is option (C).

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.

conservation of mass

mass before something happens = mass afterwards