All categories

3 years ago

Read the given expression.

Chemistry

1 answer:

Jlenok [28]3 years ago

6 0

Answer:

Choice number two. The value of "X" in this equation should be constant for all elements across a period.

Explanation:

Electrons are negative while protons are positive. Electrons are attracted to the proton but repel each other.

Consider an atom where electrons occupy more than one energy level. Consider the Bohr Model for that atom. Protons in the nucleus attract the electrons towards the center of the atom. However, at the same time, electrons in the inner shell will repel the valence electrons. That creates an outward force that pushes the valence electrons away from the atom.

The two forces mostly balance each other, but the attraction is slightly stronger. As a result, the overall force on the valence electrons is attractive. The effective nuclear charge gives the number of protons required to produce an attraction of that strength if there was no repulsion at all.

The value of effective nuclear charge is approximately the same as atomic number minus the number of inner-shell electrons. Apparently, the "X" in this question stands for the number of inner-shell electrons.

By the Aufbau Principle, all spots in the inner shell must be filled before more electrons can be added. Additionally, atoms in the same period have the same number of inner shells. As a result, the number of inner-shell electrons will be the same for all atoms in each period. Hence, the value of "X" should stay (approximately) the same across each period.

You might be interested in

Which feature does the model show accurately

Illusion [34]

We need a image to answer this sorry

3 0

3 years ago

What is the mass of 0.714 moles of Mercury (I) Chloride (Hg2Cl2)?

ArbitrLikvidat [17]

Data:

m (Sample Mass) = ?
n (Number of moles) = 0.714 mol
MM (Molar Mass) of Mercury (I) Chloride ( $Hg_{2} Cl_{2}$ )
Hg = 2*200.59 = 401.18 amu
Cl = 2*35.453 = 70.906 amu
----------------------------------------
Molar Mass $Hg_{2} Cl_{2}$ = 401.18 + 70.906 = 472.086 ≈ 472.09 amu or 472.09 g/mol

Formula:

$n = \frac{m}{MM}$

Solving:

$n = \frac{m}{MM}$
$0.714 = \frac{m}{472.09}$
$m = 337.07226\:\to\:\boxed{\boxed{m\approx 337 g}} \end{array}}\qquad\quad\checkmark$

Answer:
By approximation would be letter D) 337.2 g

8 0

3 years ago

4. Which of the following have mass? Select all that apply.

valkas [14]

All of these EXCEPT helium in a balloon

4 0

3 years ago

Your mother has an unlabeled bottle of clear liquid in the refrigerator. You pour a small cup of the liquid and taste it, and it

Nostrana [21]

The pH of the liquid would be 6 or a 5

6 0

3 years ago

In the background, you were given the reactions for the fermentation of glucose to ethanol in the production of wine from grapes

ikadub [295]

Answer:

Kombucha is a Symbiotic culture of bacteria and yeast (SCOBY), similar to mother of vinegar, containing one or more specie each of bacteria and yeast which is added to sweet tea, which jump start two processes take place. First, alcoholic fermentation during which the yeast convert sugars to alcohol under controlled conditions. After that, the bacteria converts most of this alcohol into acetic, gluconic and glucoronic and other organic acids. during both of this processes, the yeast and bacteria, feast and multiply, yielding an end beverage that is rich in variety of micro organisms and healthy acids. Source: Health-Ade.com/blog/blog/what-is-fermentation

the products formed is more rich than those of the fermentation of grapes because it is a symbiotic fermentation of yeast and bacteria

Explanation:

Kombucha is fermented slightly alcoholic, lightly effervescent sweetend black or green tea, commonly consumed for its health benefits sometimes the beverage is called kombucha tea to distinguish it from the cultures of bacteria and yeast. Kombucha is thought to have originated in manchuria where the drink is traditionally consumed or in Russia and Eastern Europe.

Source: "A mug Of Kombucha for your health?" .mayo clinic. Retrieved 2018-09-01

7 0

3 years ago