Answer:
to VSEPR theory, the shape of a molecule is related to the organization of the central atom's valence shell electrons. The valence shell electrons are all negatively charged and therefore are constantly repelling each other. This repulsion is what gives a molecule its three-dimensional shape.
The correct answer is:
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" F and Br , because they are in the same group" .
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Note:
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Choice [B]: "F and Br ; because they are in the same period" ; is incorrect; since "F" and "Br" are not in the same "period" (that is, "row").
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Choice [C]: "Na and Mg; because they are in the same group {"column"} ; is incorrect; since: "Na" and "Mg are NOT in the same group {"column"].
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Choice [D]: "Na and Mg" ; because they are in the same period {"row"}; is incorrect. Note: "Na" and "Mg" are, in fact, in the same period {"row"}. However, as aforementioned, {Mg and Na} are not in the same group {"column".}.
Note: The similiarities in physical and chemistry properties among elements are determined and organized — or tend to be so—by "groups" {"columns"} — NOT by "periods" {rows}.
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The sun is my black hole and technically is also the way that urnanus comes in contact with suck m wee wee
D. 0.2 M
The concentration of a solution is basically the ratio of the solute present to the solvent in the solution. This is an intrinsic property, independent of the amount of solution that is present. A similar example is that of density. No matter the size of a sample, the density and concentration of that sample remain constant.
for 39g water solute dissolved at 20C = solubility ( g/ 100 g H2O ) × mass of water = ( 11g / 100g H2O ) × 39g H2O = 4.29 g
amount of solute dissolved at 30 C =
= 23 / 100 * 39 = 8.97 g
Amount of extra solute dissolved = 8.97 - 4.29 = 4.7 g
