Animal fibers are fibers from animals and consist mainly of protein. They contain not only silk fiber from silkworms and fur fiber from sheep wool but also collagen fiber extracted from animal skins, chitin from crustaceans, and shellfish like shrimp and chitosan made by deacetylating chitin.
Answer:
Explanation:
F2 have the weakest attraction to each other because of higher electronegativity when they are brought close to each other they repel each other
Answer:
B.
Explanation:
Propanal is an organic compound with the formula CH3CH2CHO. Aldehyde is colorless, flammable and a slightly fruity odor.
The answer is; B
Initially, the earth’s atmosphere was mainly filled with carbon dioxide and methane. However, with the evolution of photosynthetic organisms, the composition of the atmosphere changed to be mainly oxygen. This geological time is referred to as the great oxygenation event. The high oxygen levels resulted in oxidation of most the upper lithosphere.
The answer is; B
During this time, the organism on earth began to evolve and live on land. Therefore these geologic events are marked by fossilized of dead primitive organisms such as archaebacteria within the early rocks