I give 10 points for 3 tasks + BRAINLIEST!!!!

Chemistry

1 answer:

Marta_Voda [28]3 years ago

6 0

21. F, Cl and Br.

22. Since it is in Group 3 it will have 3 valence electrons. When you draw the Lewis structure for Aluminum you'll put three "dots" or valence electrons around the element symbol.

23. you would need 2 group 17's for every 1 group 2

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Can Individual atoms be moved and rearranged ?

andriy [413]

Answer:

Yes

Explanation:

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3 years ago

Calculate the molarity when 135 g of KCl is dissolved to make a 2.50 L solution. Round to two significant digits.

inysia [295]

Explanation:

$\textrm{Molarity of a solution}=\frac{\textrm{Number of moles of solvent}}{\textrm{Volume of solution in Liters}}$

We are given a $2.50L$ solution which contains $135g$ of $KCl$ .

To calculate number of moles of $KCl$ present, we need to find it's molar mass from charts. Molar Mass of $KCl$ is known to be $74.55\frac{g}{Mol}$ .

Number of moles of $KCl$ present = $\frac{\textrm{Given weight}}{\textrm{Molar Mass}}\textrm{ = }\frac{135g}{74.55\frac{g}{Mol}}\textrm{ = }1.81087mol$