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3 years ago

Which is easier to remove: a valence electron from, Li or Na? Explain why.

Chemistry

1 answer:

scZoUnD [109]3 years ago

7 0

The atomic number of Li is 3

Electron configuration of Li : 1s² 2s¹

The atomic number of Na is 11

Electron configuration of Na : 1s²2s²2p⁶3s¹

Thus there is one electron in the valence shell of Li (2s¹) and that of Na (3s¹). However, the valence electron in Na is in a shell that is farther away from the nucleus compared to that of Li. As a result, the Na valence electron will be held less tightly by the nucleus i.e. it will experience a reduced nuclear attraction and can be removed easily than the Li 2s electron.

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What term refers to the small parts of a cell that carry out different functions?

deff fn [24]

That would be C. Organelles

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4 years ago

A sample of an unknown gas effuses in 14.4 min. An equal volume of H2 in the same apparatus under the same conditions effuses in

Elena-2011 [213]

Answer:- molar mass of the unknown gas is 71.5 gram per mol.

Solution:- From Graham's law of effusion rates, the rate of effusion of a gas is inversely proportional to the square root of it's molar mass.

When we compare the effusion rates of two gases then the formula for Graham's law is:

$\frac{rate_1}{rate_2}=\sqrt{\frac{M_2}{M_1}}$

In this formula, V stands for volume and M stands for molar mass

Rate is volume effused per unit time. Since, the volumes are same, the formula could be written as:

$\frac{t_2}{t_1}=\sqrt{\frac{M_2}{M_1}}$

let's say in formula, subscript 1 is for hydrogen gas and 2 is for the unknown gas.

Molar mass of hydrogen is 2.02 grams per mol and the time taken to effuse it is 2.42 min. The time taken to effuse the unknown gas is 14.4 min and we are asked to calculate it's molar mass. let's plug in the values in the formula:

$\frac{14.4}{2.42}=\sqrt{\frac{M_2}{2.02}}$

$5.95=\sqrt{\frac{M_2}{2.02}}$

doing squares to both sides:

$35.4=\frac{M_2}{2.02}$

$M_2=35.4*2.02$

$M_2=71.5$

So, the molar mass of the unknown gas is 71.5 grams per mol.

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4 years ago

Where do you find elements grouped that have the most similar physical and chemical properties?

Svetach [21]

Answer:

Each element within a group has similar physical or chemical properties because of its atom's outermost electron shell (most chemical properties are dominated by the orbital location of the outermost electron).

Explanation:

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3 years ago

Write the expression for the equilibrium constant for this reaction. 2N205(g) <==> 4N02(g) + 02(g)

Elis [28]

Answer:

K = [NO₂]⁴[O₂] / [N₂O₅]²

Explanation:

Based on the chemical equilibrium reaction:

2 N₂O₅(g) ⇄ 4NO₂(g) + O₂(g)

The equilibrium reaction is obtained as the ratio between the multiplication of the concentrations of the reactants over the products powered to its reaction coefficient. That is:

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3 years ago

Would any Chemistry braniacs be kind enough to help explain how to work these out? Any help is appreciated, thanks

o-na [289]

Answer:

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3 years ago