1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
o-na [289]
3 years ago
9

Suppose a laboratory wants to identify an unknown pure substance. The valence electrons of the substance's atoms feel an effecti

ve nuclear charge of +4. If the unknown substance has a higher electronegativity value than silicon (Si), what other characteristics would you expect the substance to exhibit?
It would have larger atomic radii than Si and higher ionization energies than Si.
It would have larger atomic radii than Si and lower ionization energies than Si.
It would have smaller atomic radii than Si and higher ionization energies than Si.
It would have smaller atomic radii than Si and lower ionization energies than Si.
Chemistry
1 answer:
zalisa [80]3 years ago
6 0

Answer:

  • The answer is the third option in the list:<em> It would have smaller atomic radii than Si and higher ionization energies than Si.</em>

Explanation:

The<em> effective nuclear charge</em> is that portion of the total nuclear charge that a given electron in an atom feels.

Since, the inner electrons repel the outer electrons, t<em>he effective nuclear charg</em>e of a determined electron is the sum of the positive charge (number of protons or atomic number) that it feels from the nucleus less the number of electrons that are in the shells that are are closer to the nucleus than the own shell of such (determined) electron.

Mathematically, <em>the effective nuclear charge (Zeff)</em> is equal to the atomic number (Z) minus the amount (S) that other electrons in the atom shield the given (determined) atom from the nucleus.

  • Zeff = Z - S.

Since, the valence electrons are the electrons in the outermost shell of the atom, you can find certain trend for the value Zeff.

Let's look at the group to which Si belongs, which is the group 14. This table summarizes the relevant data:

Element   Z   Group   # valence electrons     S                      Zeff = Z - S

C              6      14                      4                     6 - 4 = 2             6 -  2 = +4

Si             14     14                      4                     14 - 4 = 10         14 - 10 = +4

Ge           32     14                     4                     32 - 4 = 28       32 -28 = +4

Sn           50     14                     4                     50 - 4 = 46       50 - 46 = +4

Pb           82     14                     4                     82 - 4 = 78        82 - 78 = +4  

With that, you have shown that the valence electrons of the unknown substance's atoms feel an effective nuclear charge of +4 and you have a short list of 4 elements which can be the unknown element: C, Ge, Sn or Pb.

The second known characteristic of the unknown substance's atoms is that it has a <em>higher electronegativity than silicon (Si)</em><em>.</em>

So, you must use the known trend of the electronegativity in a group of the periodic table: the electronegativity decreases as you go down in a group. So, three of the elements (Ge, Sn, and Pb) have lower electronegativity than Si, which has left us with only one possibility: the element C. The valence electrons of carbon (C) atoms feel an effective nuclear charge of +4 and it carbon has a higher electronegativity than silicon.

Other two periodic trends attending the group number are the <em>atomic radii and the ionization energy</em>.

The atomic radii generally increases as you go from top to bottom in a group. This is because you are adding electrons to new higher main energy levels. So, you can conclude that the originally unknwon substance (carbon) has a smaller atomic radii, than Si.

The ionization energies generally decreases as you go from top to bottom in a group. This os due to the shielding effect: as seen, the effective nuclear charge of the atom's valence electrons remains constant, while the distance of the electrons from the nucleus increases (the valence electrons are farther away from the nucleus), which means the upper the element in a given group, the larger the ionization energy of the atoms.

With this, our conclusions about the unnkown substance are:

  • Since it has a higher electronegativity value than silicon (Si), it is right up of Si, and there is on only element possible element than can be (C).

  • Since, it is upper than silicon (Si), it would have smaller atomic radii.

  • Due to the shielding effect, it would have larger ionization energies.

  • The answer is the third option in the list: It would have smaller atomic radii than Si and higher ionization energies than Si.

You might be interested in
The ability to do work or cause change is
Ilia_Sergeevich [38]
The ability to do work or cause change is
Energy
4 0
3 years ago
What is the speed of a car that has traveled 100 miles in 20 hours?<br> |
77julia77 [94]

Answer:

5 mph

Explanation:

100 miles, 20 hours (divide by 2)

50 miles,    10 hours (divide by 2)

25 miles,    5 hours (divide by 2)

divide both sides by 5

5 miles,     1 hour

3 0
3 years ago
Read 2 more answers
Which statement best explains why magnesium and chlorine combine in a 1:2 ratio?
denpristay [2]

The statement that best explains why magnesium and chlorine combine in a 1:2 ratio is; Magnesium has two valence electrons, and chlorine can accept one electron in its outer shell.

The number of electrons that an atom of an element has in its outermost shell determines the chemical formula of the compounds formed by atoms such elements.

Magnesium is in group 2, as such it has two electrons in its outermost shell while chlorine in group 17 only accepts one electron in its outermost shell. This one electron will give chlorine an inert gas configuration while the loss of two electrons give magnesium an inert gas configuration.

Therefore; The compound MgCl2 is formed in the ratio of 1:2 because Magnesium has two valence electrons, and chlorine can accept one electron in its outer shell.

Learn more: brainly.com/question/11527546

8 0
3 years ago
What is the difference between a Group/Family and a period on the Periodic Table?
drek231 [11]

Explanation:

The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.

4 0
3 years ago
Read 2 more answers
Why would putting argon and pottassium in order of there atomic masses be wrong
coldgirl [10]
Putting them in that oder can be absolutely wrong becaus they are not in the same group of the periodic table
8 0
3 years ago
Other questions:
  • one kilogram of water (V1 = 1003 cm^3*kg-1) in a piston cylinder device at (25°C) and 1 bar is compressed in a mechanically reve
    6·1 answer
  • What is the wavelength of the matter wave associated with an electron (me= 9.1 x 10-31 kg) moving with a speed of 2.5 x 107 m/s?
    11·1 answer
  • For the reaction 3F2 + Cl2 --&gt; 2ClF3 what is the maximum amount of ClF3 which could be formed from 9.86 g of F2 and 17.46 of
    11·1 answer
  • Fe(s) is already one atom and it is gas. Why do we call it a solid?
    13·1 answer
  • What are alleles A the decoders of the dna message B two forms of single genes c the basic unit inheritance d a measurable
    6·2 answers
  • Combustion of hydrocarbons such as butane () produces carbon dioxide, a "greenhouse gas." Greenhouse gases in the Earth's atmosp
    9·1 answer
  • Which term represents a chemical reaction?
    13·1 answer
  • Propane can be turned into hydrogen by the two-step reforming process. In the first step, propane and water react to form carbon
    11·1 answer
  • What is the density of a 5 mL sample of 1.95g of Gold
    15·1 answer
  • Does the pH increase or decrease, and does it do so to a large or small extent, with each of the following additions?(a) 5 drops
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!