Answer:
Explanation:
Based on the scenario being described within the question it can be said that the most likely reason for this misconception would be that the spiral galaxies looked like clouds of gas and dust through telescopes because of their distance from Earth. During that time telescopes were still not as advanced and could only see so much, nowadays they are much more advanced and these galaxies are being analyzed and understood more clearly.
Answer:
D. atmospheric aerosols.
Explanation:
<em>Atmospheric aerosols are tiny particles that float in the air. These particles could be liquid or solid and are usually suspended primarily by direct emission into the atmosphere or secondarily by condensation process. </em>
Atmospheric aerosols have numerous effects on the biotic and abiotic factors of the environment. They alter air quality and impact human health in some cases, they can reduce atmospheric visibility, and they also reduce the amount of radiation that reaches the earth by scattering or reflecting some of the radiations from the sun back into space, leading to cooling of the atmosphere.
Half life is the time taken by a radioactive isotope to decay by half of its original mass. In this case the half life of carbon-14 is 5500 years.
The original mass is 30 g and the new mass is 3.75 g.
New mass = Original mass × (1/2)^n, where n is the number of half lives;
3.75 = 30 × (1/2)^n
1/8 = (1/2)^n
n = 3
Thus, the time taken will be; 3 × 5500 = 16500 years.
