The answer is B to prevent condensation from forming on the agar surface
pressure increases as depth increases.
<span>The </span>abundance of a chemical element<span> is a measure of the </span>occurrence<span> of the </span>element<span> relative to all other elements in a given environment. Abundance is measured in one of three ways: by the </span>mass-fraction<span> (the same as weight fraction); by the </span>mole-fraction<span> (fraction of atoms by numerical count, or sometimes fraction of molecules in gases); or by the </span>volume-fraction<span>. Volume-fraction is a common abundance measure in mixed gases such as planetary atmospheres, and is similar in value to molecular mole-fraction for gas mixtures at relatively low densities and pressures, and </span>ideal gas<span> mixtures. Most abundance values in this article are given as mass-fractions.
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This task can be easily done once we have the periodic table. From the periodic table, it can be seen that potassium is in the fourth row. Thus, it has four energy levels. If we are to use the same principle as that stated above, the number of energy levels for each are as follow:
Calcium = Ca (in periodic table) = energy levels
Iron = Fe (in periodic table) ; 4 energy levels
Nickel = Ni (in periodic table); 4 energy levels
Zinc = Zn (in periodic table) = 4 energy levels
