Answer to Question 1
ANSWER: An ordinary cloud droplet is extremely small, having an average diameter of 20 micrometers or 0.002 cm. A typical cloud droplet is 100 times smaller in diameter than a typical raindrop. If a cloud droplet is in equilibrium with its surroundings, the size of the droplet does not change because the water molecules condensing onto the droplet will be exactly balanced by those evaporating from it. If, however, it is not in equilibrium, the droplet size will either increase or decrease, depending on whether condensation or evaporation predominates.
Answer to Question 2
ANSWER: Cloud seeding has been attempted in both cold and warm clouds.
Silver iodide has a crystalline structure similar to an ice crystal, which is why it acts as an effective ice nucleus at temperatures of -4C (25F) and lower. Silver iodide causes ice crystals to form in two primary ways:
1) Ice crystals form when silver iodide crystals come in contact with supercooled liquid droplets.
2) Ice crystals grow in size as water vapor is deposited onto the silver iodide crystal.
Silver iodide is much easier to handle than dry ice, since it can be supplied to the cloud from burners located either on the ground or on the wing of a small aircraft. Although other substances, such as lead iodide and cupric sulfide, are also effective ice nuclei, silver iodide still remains the most commonly used substance in cloud-seeding projects.
An illustration of the helium atom, depicting the nucleus (pink) and the electron cloud distribution
Table 6.1 illustrates the main regime types and their differences. It breaks the regimes into four
Location of the main structures of the vessels
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Frédéric Chopin's "Raindrop" Prelude, Op 28, No. 15
A taproot system consists of a large main root together with its lateral branchings