Natural selection is the right answer hope this helps.
Answer:
Bio gas
Explanation:
Bio gas is gotten from the anaerobic breaking down of biomass especially animal waste.
PROS:
A. it is renewable: biogas is renewable and has an endless supply of material since animals are the main source when compared to fossil fuels.
B. It doesn't involve a rigorous mining exersice to get to like fossil fuels and it is in accessible abundance.
CON:
A. A lot of waste is needed for the product of biogas and the final waste (sludge) from the production process can be a huge problem to dispose off.
B. Some of the gases liberated in the manufacturing process are greenhouse gas, especially methane. These gases if let out, will contribute immensly to global warming.
Answer:
The elements in increasing order of atomic radius: oxygen, carbon, aluminum, potassium
Explanation:
The distance from the center of the nucleus to the outermost shell of the electron is known as the atomic radius of an element. The atomic radius decreases rightward along each period (row) of the table due to the increase in effective nuclear charge (the charge of the nucleus equal to the number of protons). Across a period, electrons are added to the same energy level and the increasing number of protons causes the nucleus to exert more pull on these electrons, which makes the atomic radius smaller. Atomic radius increases down each group (column) of the periodic table because of the addition of electrons to higher energy levels, which are further away from the nucleus and the pull of nucleus weakens. Another reason for the increase in atomic radius is the electron shielding effect, which is the reduction of the attractive force between a nucleus and its outer electrons due to the blocking effect of inner electrons
While moving from left to right in the second period, c
arbon comes before oxygen and so oxygen will have a smaller atomic radius than carbon. While moving down the periodic table, al
uminum comes before potassium even if they are not in the same period. So aluminum
's atomic radius will be smaller than that of potassium but bigger than that of carbon and oxygen.
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Answer:
fluid-filled cavity
Explanation:
Rhynchocoel is a fluid-filled tubular cavity present in the organisms of the phylum Nemertea. This cavity lies above the intestines of these organisms in the lower body.
Nemertea is a phylum composed of worms that can be found in shallow water.
These worms have already been classified as a branch of the Flatworms (such as Planarians), with which they are often confused. But recent embryological and molecular evidence points to a phylogenetic relationship with mollusks and annelids. They remind the Flatworms to be non-segmented flat worms. But unlike these, they have a complete bowel with mouth and anus, and a closed vascular system. The article on Planarians can be accessed here.
