<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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Answer:
percentage of water = 18.76%
Explanation:
A chemist has a sample of hydrated Li2SiF6 and it weighs 0.4813 grams.
The overall weight of the compound is 0.4813 grams.
weight of hydrated sample = 0.4813 grams.
weight of anhydrous compound = 0.391 grams
percentage weight of water = mass of water/mass of the hydrated compound × 100
mass of water = mass of hydrated compound - mass of anhydrous compound
mass of water = 0.4813 - 0.391 = 0.0903 grams.
percentage of water = 0.0903/0.4813 × 100
percentage of water = 9.03/0.4813
percentage of water = 18.761687097
percentage of water = 18.76%
Answer: Extinction
Animals on the verge of extinction are considered endangered species. Some could argue that the phrasing "threatened" is synonymous to "endangered". Some classify extinction based on if the species is completely wiped out in the wild, or if the species is completely gone (both in the wild and in zoos for instance). Extinction events are not solely due to the changes in atmosphere, but also due to lack of food or habitat, among other possible factors.
Answer:
118.4 g
Explanation:
4 Ga + 3 S₂ → 2 Ga₂S₃
According to the equation, for every 4 moles of gallium burned, 2 moles of gallium(III) sulfide.
First, convert grams of Ga₂S₃ to moles. The molar mass is 235.641 g/mol.
(200.0 g)/(235.641 g/mol) = 0.8487 mol
Use the relationship above to convert moles of Ga₂S₃ to moles of Ga.
(0.8487 mol Ga₂S₃) × (4 mol Ga)/(2 mol Ga₂S₃) = 1.697 mol Ga
Convert moles of Ga to grams. The molar mass is 69.723 g/mol.
(1.697 mol Ga) × (69.723 g/mol) = 118.4 g
Mg(c) + 237shi (4z) ¥at h2)
