<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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Your question looks a bit incomplete as you have the same contents in options a) and d). According to your list, I can't see the correct answer, but I can give you one.The difference between the potential energy of the products of the potential energy of the reactants is equal to the enthalpy of the reaction.
Answer:
pH = 12.20
Explanation:
Ca(OH)2 is a strong base, so it dissociates completely. A 0.08 M solution of Ca(OH)2 is 0.16 M OH-, since every mole of Ca(OH)2 has 2 OH-.
Calculate pOH using [OH-] = 0.16 M
pOH = -log(0.16) = 0.80
pH = 14 - pOH = 14 - 0.80 = 12.20
3 should be B hop this helps
The reason why perchloric acid is more acidic that ethane is because the hydrogen in perchloric acid is bonded to oxygen which is more electronegative than carbon.
The acidity of a substance depends largely on the ease with which the X-H bond is broken. If the electron density is tilted towards the atom X, then the X-H bond is weaker and the substance is more acidic.
The polarity of the X-Y bond depends on the electronegativity of X. In the case of perchloric acid and ethane, oxygen is more electronegative than carbon hence the O-H bond in perchloric acid is more easily broken than the C-H bond in ethane.
Learn more: brainly.com/question/14072179
