Well, for one thing, they ensure that a scientist can't claim a certain result, which might be biased and thus inaccurate, because he or she is being paid by, say, big business interests. For another, they ensure that medicines or treatments can't be made available to the public without thorough testing, replication, and peer review.
Non-polar covalent
Explanation:
Propane is made up of non-polar covalent bonds and it can be expected to dissolve in hexane and to not dissolve in water.
Propane is an hydrocarbon gas.
It forms by sharing of electrons between two atoms with very low electronegativity differences.
This differences results in equal sharing of the shared electron. Therefore they form a non-polar covalent bond.
Water is a polar covalent compound and cannot dissolve compounds that are not polar like propane.
Propane will only dissolve in a like substance like hexane which is equally non-polar.
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Covalent compounds brainly.com/question/3109255
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There are two naturally occurring isotopes of gallium: mass of Ga-69 isotope is 68.9256 amu and its percentage abundance is 60.11%, let the mass of other isotope that is Ga-71 be X, the percentage abundance can be calculated as:
%Ga-71=100-60.11=39.89%
Atomic mass of an element is calculated by taking sum of atomic masses of its isotopes multiplied by their percentage abundance.
Thus, in this case:
Atomic mass= m(Ga-69)×%(Ga-69)+X×%(Ga-71)
From the periodic table, atomic mass of Ga is 69.723 amu.
Putting the values,

Thus,

Rearranging,

Therefore, mass of Ga-71 isotope is 70.9246 amu.