A group of cells doing the same job forms a tissue. A group of tissues working together forms an organ. Organs work in groups, too. A group of organs doing the same job is called a system.
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Most of the elements important in biology need 8 electrons in their outermost shell
Answer:
ummm well you have to go to school I
A. Scientific results presented by a scientist should be reproducible anywhere in the world, without this, the results can not be accepted as theory.
Answer: The best way to promote the process are:
--> Add a bit of solid as a seed crystal.
--> Scratch the bottom of the flask gently with a stirring rod.
Explanation:
A crystal growth is seen is SUPERSATURATED solutions which contains more solute than it can normally dissolve at that given temperature. It is usually very UNSTABLE and capable of releasing the excess solute if disturbed, either by shaking or seeding with a tiny crystals.
Crystallization can be used for the separation of two salts with different solubilities as well as for purification of a soluble salt that contains insoluble solid impurities. Recrystallization improves the validity of the process. Crystallization can be initiated by:
--> Scratching the bottom of the flask gently with a stirring rod: scratching initiates crystallization by providing energy from the high-frequency vibrations.
--> Adding a bit of solid as a seed crystal: Seed crystals create a nucleation site where crystals can begin growth.
