Answer:
When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Stone surface material may be lost all over or only in spots that are more reactive.
Explanation:
You might expect that sheltered areas of stone buildings and monuments would not be affected by acid precipitation. However, sheltered areas on limestone and marble buildings and monuments show blackened crusts that have peeled off in some places, revealing crumbling stone beneath. This black crust is primarily composed of gypsum, a mineral that forms from the reaction between calcite, water, and sulfuric acid. Gypsum is soluble in water; although it can form anywhere on carbonate stone surfaces that are exposed to sulfur dioxide gas (SO2), it is usually washed away. It remains only on protected surfaces that are not directly washed by the rain.
Answer and Explanation:
The lymph node are the sites for the formation of lymphocytes and monocytes. These are concerned with antibody formation and phagocytosis of foreign materials respectively. In the lymph nodes, bacteria and other harmful materials are removed from lymph.
Ribosomes are the organelles of the cell which are involved in protein-synthesis (I. e. process of making proteins)
Pacinian corpuscles are rapidly-adapting, deep receptors that respond to deep pressure and high-frequency vibration.
