<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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That when water is boiled in a open beaker and it disappears that it evaporates into the air
Ions are stable atoms of elements formed when original atoms loose or gain electrons to form stable configuration. Anions are negatively charged ions formed when atoms gain electrons while cations are the positively charged ions formed when atoms loose electrons. In this case a charge of +1 means an atom lost one electron to form a stable configuration. Therefore, the correct answer is A
<span>Friction creates heat which in turn can lead to deviations from the original size and shape of a part.
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