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3 years ago

What is the electron configuration of an isolated s atom?

1 answer:

6 0

Sulfur possesses 16 electrons in its ground state. The first shell of sulfur has 2 electrons. The next shell has 8 electrons. The third and final shell of sulfur has 6 electrons. The electronic configuration is written as:

1s², 2s², 2p⁶, 3s², 3p⁴

This means that sulfur exhibits a valency of -2, which is true in many cases.

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Who's good at chemistry? Maybe you can help me out?

Anvisha [2.4K]

Formula is Naf
charge is Flourine ion
symbol is ∨∨∨∨
hope that helped

4 0

3 years ago

As a technician in a large pharmaceutical research firm, you need to produce 250. mL of a potassium dihydrogen phosphate buffer

Reika [66]

Answer:

We will need 147.772 mL of KH2PO4 to make this solution

Explanation:

For this case we can give the following equation:

H2PO4 - ⇄ H+ + HPO42-

With following pH- equation:

pH = pKa + log [HPO42-]/[H2PO4-]

7.05 = 7.21 + log [HPO42-]/[H2PO4-]

-0.16 = log [HPO42-]/[H2PO4-]

10^-0.16 = [HPO42-]/[H2PO4-]

0.6918 = [HPO42-]/[H2PO4-]

Let's say the volume of HPO42-= x then the volume of H2PO4- will be 250 mL - x

Since both have a concentration of 1M = 1 mol /L

If we plug this in the equation 0.6918 = [HPO42-]/[H2PO4-]

0.6918 = x / (250 - x)

0.6918*250 - 0.6918x = x

172.95 = 1.6918x

x = 102.228 mL

The volume of HPO42- = 102.228 mL

Then the volume of H2PO4- = 250 - 102.228 = 147.772 mL

To control this we can plug this in the pH equation

7.05 = 7.21 + log [HPO42-]/[H2PO4-]

7.05= 7.21 + log (102.228 / 147.772) = 7.05

We will need 147.772 mL of KH2PO4 to make this solution

3 0

3 years ago

Which of the following best defines base isolation?(1 point)

jekas [21]

Base isolation is a method of earthquake resistant engineering where a structure is separated from the ground by isolation units that reduces the impact of seismic vibration energy. So, the last answer choice would be the best definition.

3 0

3 years ago

A drought is best defined as

Lapatulllka [165]

A drought is a period of drier-than-normal conditions that results in water-related problems.<span> When rainfall is less than normal for several weeks, months, or years, the flow of streams and rivers declines, water levels in lakes and reservoirs fall, and the depth to water in wells increases.</span>

5 0

3 years ago

A student carries out this chemical reaction in a beaker:

nydimaria [60]

Answer:The correct answer is option (C).

Explanation:

$Zn+CuCl_2\rightarrow Cu+ZnCl_2$

After the reaction between Zinc and copper(II) chloride, Zinc chloride and copper will be obtained as a product. This reaction occurs because zinc is more reactive than copper which displaces the copper from its aqueous solution.

The student will expect to find copper metal at bottom of the beaker with aqueous solution of zinc chloride.

Hence the correct answer is option (C).

7 0

3 years ago