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vazorg [7]
2 years ago
11

SOMEONE HELP ASAP I NEED TO FIND AN ANSWER

Chemistry
1 answer:
astra-53 [7]2 years ago
6 0

Answer:

A) Q + XZ = X + QZ is a single displacement reaction.

B) Q + Z = QZ is a synthesis reaction

C) QT = Q + T is a decomposition reaction

D) QT + XZ = QZ + XT is double replacement reaction.

Explanation:

A) Q + XZ = X + QZ

This is a single displacement reaction because it is one in which one element is substituted for another one in a compound. In this case X is substituted for Q.

B) Q + Z = QZ

This is a synthesis reaction because Q and z combine to form a single product QZ.

C) QT = Q + T

This is a decomposition reaction because the compound QT breaks down to form 2 simpler substances Q and T.

D) QT + XZ = QZ + XT

Thus is a double replacement reaction because QT and XZ have exchanged cations to form new compounds QZ and XT

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Predict with a reason, what would happen to a packet of potato chips that is packed with air when it is taken to o high mountain
olga2289 [7]

Explanation:

If you bring an unopened bag of potato chips aboard an airplane you'll notice that the bag puffs up as the plane ascends to a higher altitude explain why this happens using the information and terminology you learned in this module

6 0
3 years ago
Suppose a laboratory wants to identify an unknown pure substance. The valence electrons of the substance's atoms feel an effecti
zalisa [80]

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.

6 0
3 years ago
Plz help ya' girl out!<br> Label the parts of whatever that is <br> Plz giving brainliest!
Burka [1]

Answer:

BRAINLIEST PLEASE!!!

A = Smooth Endoplasmic Reticulum

B = Vacuole

C = Mitochondria (Plural)

D = Nucleolus

E = Cell Wall

Explanation:

This is obviously a plant cell. Animal cells do not have cell walls(E), and most animal cells will not have a vacuole(B). Smooth Endoplasmic Reticulum: This produces protiens (contains ribosomes) but when looked through a microscope, will appear to be smooth. The vacuole(B) is like a storage for the plant cell, and it helps support the plant cell. This is the reason why plants “droop” when you don’t water them for a long time. Mitochondia (Plural) processes nutrients for the cell. The nucleolus(D) covers the nucleus. It’s main function is to process RNA and combine it with proteins. The cell wall(E) helps support and protect the cell.

4 0
2 years ago
In an ionic compound, the size of the ions affects the internuclear distance (the distance between the centers of adjacent ions)
jeyben [28]

Answer:

Li2S> Na2S> K2S> CsS

Explanation:

The lattice energy of ionic species depends on the relative sizes of ions in the ionic compounds. As the size of ions increases, the lattice energy decreases and vice versa.

When the size of the anions are the same, the lattice energy now depends on the relative sizes of the cations. Therefore, since all the compounds are sulphides and the order of magnitude of ionic sizes is: Li^+ < Na^+ < K^+ < Cs^+.

Therefore, the order of decrease in lattice energy is; Li2S> Na2S> K2S> CsS

7 0
3 years ago
Passing an electric current through a sample of water (H2O) can cause the water to decompose into hydrogen gas (H2) and oxygen g
Setler [38]
The balanced chemical reaction is:

<span>2H2O= 2H2 + O2
</span>
We are given the amount of oxygen to be produced in the reaction. The starting point for the calculations will be this amount.

50 g ( 1 mol O2 / 32 g O2 ) ( 2 mol H2O / 1 mol O2 ) ( 18.01 g H2O / 1 mol H2O) = 56.28 g of H2O is needed.

Therefore, the correct answer is the last option.
8 0
3 years ago
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