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3 years ago

How does silicon dioxide become a covalent bond. (explain)

1 answer:

4 0

Silicon dioxide is SiO2. Silicon has 4 valence electrons, while each oxygen has 6 valence electrons. This can be shown as
** * *
** O * * Si * * O **
* * **
At points where there is one valence electron, represented by a lone *, the electrons will be 'shared' between the atoms. This will make silicon dioxide appear as
** *--------------- *
** O *--* Si * ------ * O **
*------- * **
, as the lines with no arrows indicate that each electron moves between the atoms, and does not stay with one forever.

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How to solve this: a small dog has consumed a dangerous amount of apap. the vet has ordered: rx acetylcysteine 150mg/kg/stat. yo

Fantom [35]

Given:
Stock dose/concentration of 20% Acetylcysteine (200 mg/mL)
150 mg/kg dose of Acetylcysteine
Weight of the dog is 13.2 lb

First we must convert 13.2 lb to kg:
13.2 lb/(2.2kg/lb) = 6 kg

Then we must calculate the dose:
(150 mg/kg)(6kg) = 900 mg

Lastly, we must calculate the dose in liquid form to be administered:
(900 mg)/(200 mg/mL) = 4.5 mL

Therefore, 4.5 mL of 20% Acetylcysteine should be given.

3 0

3 years ago

Rank the following elements by effective nuclear charge, Zeff, for a valence electron. F LI Be B N

Stels [109]

Answer:

Rank in increasing order of effective nuclear charge:

Li < Be < B < N < F

Explanation:

This explains the meaning of effective nuclear charge, Zeff, how to determine it, and the calculations for a valence electron of each of the five given elements: F, Li, Be, B, and N.

1) Effective nuclear charge definitions

While the total positive charge of the atom nucleus (Z) is equal to the number of protons, the electrons farther away from the nucleus experience an effective nuclear charge (Zeff) less than the total nuclear charge, due to the fact that electrons in between the nucleus and the outer electrons partially cancel the atraction from the nucleus.

Such effect on on a valence electron is estimated as the atomic number less the number of electrons closer to the nucleus than the electron whose effective nuclear charge is being determined: Zeff = Z - S.

2) Z eff for a F valence electron:

F's atomic number: Z = 9
Total number of electrons: 9 (same numer of protons)
Period: 17 (search in the periodic table or do the electron configuration)
Number of valence electrons: 7 (equal to the last digit of the period's number)
Number of electrons closer to the nucleus than a valence electron: S = 9 - 7 = 2
Zeff = Z - S = 9 - 2 = 7

3) Z eff for a Li valence eletron:

Li's atomic number: Z = 3
Total number of electrons: 3 (same number of protons)
Period: 1 (search on the periodic table or do the electron configuration)
Number of valence electrons: 1 (equal to the last digit of the period's number)
Number of electrons closer to the nucleus than a valence electron: S = 3 - 1 = 2
Z eff = Z - S = 3 - 2 = 1.

4) Z eff for a Be valence eletron:

Be's atomic number: Z = 4
Total number of electrons: 4 (same number of protons)
Period: 2 (search on the periodic table or do the electron configuration)
Number of valence electrons: 2 (equal to the last digit of the period's number)
Number of electrons closer to the nucleus than a valence electron: S = 4 - 2 = 2
Z eff = Z - S = 4 - 2 = 2

5) Z eff for a B valence eletron:

B's atomic number: Z = 5
Total number of electrons: 5 (same number of protons)
Period: 13 (search on the periodic table or do the electron configuration)
Number of valence electrons: 3 (equal to the last digit of the period's number)
Number of electrons closer to the nucleus than a valence electron: S = 5 - 3 = 2
Z eff = Z - S = 5 - 2 = 3

6) Z eff for a N valence eletron:

N's atomic number: Z = 7
Total number of electrons: 7 (same number of protons)
Period: 15 (search on the periodic table or do the electron configuration)
Number of valence electrons: 5 (equal to the last digit of the period's number)
Number of electrons closer to the nucleus than a valence electron: S = 7 - 5 = 2
Z eff = Z - S = 7 - 2 = 5

7) Summary (order):

Atom Zeff for a valence electron

Li 1

Be 2

Conclusion: the order is Li < Be < B < N < F

6 0

3 years ago

HCl, NaCl, and CO are all examples of chemical properties bonds formulas changes

Ainat [17]

Answer:

HCL, NACL and CO are the examples of chemical formulas

4 0

2 years ago

2. What mass of water absorbs 6700 J of heat to raise the temperature from 283K to 318K?

Alexxandr [17]

Answer:

Q = mcT ...you can either substitute the molar heat capacity of water in the place of c or the specific heat capacity of water.

Explanation:

7 0

2 years ago

Calculate the volume of this irregular solid to the nearest cubic centimeter

EleoNora [17]

Answer:

8 cm3

Explanation:

The volume of this irregular solid will calculated as the difference between the final volume and the initial volume;

The final volume of the water and the solid is 25 ml

The initial volume of the water alone was 17 ml

The volume of the irregular solid is thus approximately;

25 - 17 = 8 ml

We then use the conversion;

1 cm3 = 1 mL

Thus the volume of the solid is 8 cm3

6 0

3 years ago

Read 2 more answers