Which element has a complete valence electron shell? selenium (Se) oxygen (O) fluorine (F) argon (Ar)

Chemistry

2 answers:

asambeis [7]3 years ago

5 0

Answer:

Argon (Ar)

Explanation:

kirill115 [55]3 years ago

3 0

Answer:

oxygen (O)

Explanation:

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Whuch expression is equal to the number of grams in 2.43 kg

schepotkina [342]

2.43*1000.

There are 1000 grams in a kilogram

7 0

3 years ago

A 13 g sample of P4010 contains how many

Alex777 [14]

Answer:

$\large \boxed{5.5 \times 10^{22}\text{ molecules of P$_{2}$O}_{5}}$

Explanation:

You must calculate the moles of P₄O₁₀, convert to moles of P₂O₅, then convert to molecules of P₂O₅.

1. Moles of P₄O₁₀

$\text{Moles of P$_{4}$O}_{10} = \text{13 g P$_{4}$O}_{10} \times \dfrac{\text{1 mol P$_{4}$O}_{10}}{\text{283.89 g P$_{4}$O}_{10}} = \text{0.0458 mol P$_{4}$O}_{10}$

2. Moles of P₂O₅

P₄O₁₀ ⟶ 2P₂O₅

The molar ratio is 2 mol P₂O₅:1 mol P₄O₁₀

$\text{Moles of P$_{2}$O}_{5} = \text{0.0458 mol P$_{4}$O}_{10} \times \dfrac{\text{2 mol P$_{2}$O}_{5}}{\text{1 mol P$_{4}$O}_{10}} = \text{0.0916 mol P$_{2}$O}_{5}$

3. Molecules of P₂O₅

$\text{No. of molecules} = \text{0.0916 mol P$_{2}$O}_{5} \times \dfrac{6.022 \times 10^{23}\text{ molecules P$_{2}$O}_{5}}{\text{1 mol P$_{2}$O}_{5}}\\\\= \mathbf{5.5 \times 10^{22}}\textbf{ molecules P$_{2}$O}_{5}\\\text{There are $\large \boxed{\mathbf{5.5 \times 10^{22}}\textbf{ molecules of P$_{2}$O}_{5}}$}$