he answer is because <span>samples of air taken over erupting volcanoes shows that volcanoes
contribute a small amount of chlorine in the stratosphere compared to CFCs. Volcanic
eruptions account for a large instability of chlorine from land to the
atmosphere on a yearly basis. This is in addition to chlorine that enters the
atmosphere from sea spray, industrial processes and biological gases which are
from CFCs. All of these inputs happen near or at the base of the atmosphere. Very
little of the material emitted from volcanoes makes it up into the upper
reaches of our atmosphere which is the stratosphere where it could touch the
ozone layer. However, most of it is believed to be deposited lower down which
is in the troposphere, where it then rained out back to the surface of the
earth.</span>
Answer:
Chlorophyll is a green pigment found in chloroplast in plants. It absorbs sunlight during the process of photosynthesis. It is a chelate molecule. In a chelate molecule a central metal ion forms bonds with a large organic molecule made of carbon, hydrogen and other elements like nitrogen or oxygen.
In chlorophyll, magnesium is the central metal ion and it is bonded to a large organic molecule called as porphyrin. Porphyrin constitutes four nitrogen atoms to which the central magnesium is bonded in square planar arrangement. Since chlorophyll is responsible for the green color of the leaves, more the green color more the chlorophyll content and more is the nitrogen content. Hence, chlorophyll meter measures this green light and finds out if the plant needs more or less nitrogen.
They are among the first
colonizers of an environment. This way they break down rocks and make nutrients available for other plants. They help in retention
of water in a habitat and also shelter many microorganisms.
They also decompose organic matter hence play an
important role in the cycling of nutrient in the environment.
