what is the wavelength of a photon emitted when an electron jumps from n=2 to n= 1 energy level of a single ionized helium atom ?​

Answer:

The answer to this question is True

Answer:

A

Explanation:

We are given that the molar mass of boron triflouride BF₃ is 67.81 g/mol. We want to determine the number of molecules of BF₃ in 2 g of BF₃.

Recall that there are 6.02 × 10²³ molecules in any mole of a substance. In other words, there are 6.02 × 10²³ BF₃ molecules in a mole of BF₃. Starting with the initial value, multiply:

[tex]\displaystyle \begin{aligned} 2\text{ g BF$_3$}&\cdot \frac{1\text{ mol BF$_3$}}{67.81 \text{ g BF$_3$}} \cdot \frac{6.02\times 10^{23} \text{ molecules BF$_3$}}{1 \text{ mol BF$_3$}} \\ \\ &= 1.776 \times 10^{22} \text{ molecules BF$_3$}\end{aligned}[/tex]

Hence, our answer is A.

*Perhaps it rendered the values incorrectly, but since we started with only 2 g of BF₃, our resulting calculation should only contain one significant digit. Hence, the correct answer should be 2 × 10²² molecules of BF₃.

The molecules of  BF₃ that are there in 2 g is 1.776 × 10²² molecules and the correct option is option A.

The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.

A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.

Given,

Molar mass of BF₃ = 67.81 g/mol

Mass = 2g

Moles = mass / molar mass

= 2 / 67.81

= 0.029 moles

1 mole = 6.023 × 10²³

0.029 moles = 6.023 × 10²³ × 0.029

= 1.776 × 10²² molecules

Thus, the ideal selection is option A.

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Answer:

The gravitational force at the center of the Earth is 0.

The mass of CO2 obtained in the reaction by stoichiometry is 30.8 g.

The equation of the reaction is;

2HCl(aq) + CaCO3(s) -----> CaCl2(aq) + H2O(l) + CO2(g)

The mass of the HCl reacted is obtained from;

Density = mass/volume

Mass = Density × volume =  1.140 g/mL ×  43.435 mL = 49.5 g

Number of moles of HCl =  49.5 g/36.5 g/mol = 1.4 moles

If 2 moles of HCl reacts produces 1 mole of CO2

1.4 moles of HCl produces x moles of CO2

x = 1.4 moles × 1 mole/ 2 moles = 0.7 moles

Mass of CO2 produced = 0.7 moles  x 44 g/mol = 30.8 g

In the second case, the same volume of acid is used hence the same mass of CO2 is obtained.

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The electronic configuration of magnesium is:

1s² 2s² 2p⁶ 3s² = [Ne] 3s²

This means that for a magnesium atom, in order to have its outermost orbital full, the easiest way would be to lose the two outermost electrons. This is seen in its relatively low first two ionization energies. The third ionization energy is several times higher because the ion would move from a stable form to an highly unstable form. (Mg⁺² → Mg⁺³ + e⁻).

Sodium only has one electron in its outermost orbital, so its first ionization energy would be several times lower than the second.

Answer:

I think it is a)in freshwater lakes,rivers,and stream

Answer:

a) in freshwater lakes, rivers, and streams

Answer:

The answer would be oxygen.

How you can check to make sure your work is error-free is by:

Hope this Helps

Answer:

6.023×10^23

Explanation:

Molecular mass= 2 (H)+1 (O) =2*1+1*16=2+16= 18 gm per 1gm molecule of water

Answer:

“Rams Caught in a Thicket” as an allusion to the biblical story of Abraham. They more likely represent goats, which could often be seen standing on their hind legs, to reach leaves in the trees, as seen here.

Explanation:

What do you mean by 'how many oxygen'?

oxygen atoms? or oxygen percentage?

if oxygen atoms is 12 atoms

Answer:

flour is the main ingredient sooo you need flour,sugar,salt milk,eggs,vegetable oil,vanilla optional.you can add baking powder or baking soda optional.

This question is recalling the behavior of real gases in contrast to ideal gases, defined by the van der Waals equation and the ideal gas law respectively, and a reason behind the increasing discrepancy is required.

In such a way, we can start by considering the attached picture in which the choices are shown and clearly, the answer is "as the polarity of the molecules increase".

The aforementioned can be explained with the concept of intermolecular forces, because ideal gas theory states that ideal gas molecules do not interact one to another, and, as the polarity of the molecules increase, these intermolecular forces increase their frequency and strength, and will lead to the formation of associations, which fail to be numerically modelled by simple equations of state such as van der Waals, Redlich-Kwong, Peng-Robinson, etc,.

These associations are, of course, thoroughly neglected by the ideal gas law whereas the ones included in the van der Waals equation, which are not the most reliable, merely attempt to approach this phenomenon, which cause the mentioned discrepancy. As an additional data, robust equations of state, such as CPA (cubic plus association) are able to provide reliable results when working with highly polar gases but turn out really tough to work with due to its mathematical complexity.

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Answer:

A carbon dioxide and oxygen

Answer:

pangea

Explanation:

Answer:

absorption or precipitation or by both

Explanation:

The maximum amount of a substance that can be dissolved in a solvent at a given temperature is referred to as its solubility.

Sucrose has a solubility of 320 g/100 g H2O at 70°C.

Sucrose has a solubility of 320 g/100 g H2O at 70°C.

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The charge on iron (Fe) in iron sulfate (FeSO₄) is equal to +2. Therefore, option (D) is correct.

The ionic charge can be described as the oxidation number of the chemical species. The cation carries a positive ionic charge while Anion carries a negative ionic charge. The number of electrons gained or lost by an atom decides the charge carried by ions.

In the modern periodic table, the elements placed on the left side are electropositive and act as metals because they can donate one or more electrons. The elements placed on the right side are electronegative as they can accept one or more electrons and get a negative charge on their ions.

Considering that the charge on the iron is x, We know that charge on the sulfate ion is -2.

x - 2 = 0

x = +2

Therefore, the charge on iron (Fe) in iron sulfate (FeSO₄) is +2.

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Answer:

H₂ is the limiting reactant

Explanation:

Balanced equations demonstrate the ratios of all reactants and products in terms of the number of atoms/molecules or moles;

In the given reaction:

1 mol of N₂ reacts with 3 mol of H₂ to produce 2 mol of NH₃

So the ratio of N₂ to H₂ to NH₃ will be 1:3:2

If we have 3 moles of N₂, we can apply the ratio to find that it will react with 9 moles of H₂ (3× the moles of N₂) to produce 6 moles of NH₃ (2× the moles of N₂);

Similarly, if we have 5 moles of H₂, then applying the ratio, we find that ⁵/₃ or 1.66... moles of N₂ (¹/₃× the moles of H₂) react with 5 moles of H₂ to produce ¹⁰/₃ or 3.33... moles of NH₃ (²/₃× the moles of H₂);

In order for all of the 3 moles of N₂ to react, it would require 6 moles of H₂;

There is only 5 moles of H₂ available, meaning there will be an excess of N₂;

5 moles of H₂ will react with 1.66... moles of the N₂, leaving 1.33... or ⁴/₃ moles of N₂ unreacted;

If the N₂ is in excess, then the H₂ is limited (i.e. the limiting reactant)

Answer:

284.48 g/mol

Explanation:

You can find the molar mass of any molecule by looking at a periodic table and adding up all of the masses of each element. When you do this with stearic acid, you get somewhere around 284.5 g/mol. Hope this helped!

Answer:

Vitamins are classified as either fat soluble (vitamins A, D, E and K) or water soluble (vitamins B and C). This difference between the two groups is very important. It determines how each vitamin acts within the body.

Answer:

D. 17,190 years old

Answer:

6.022 × 1023

Explanation:

1 mole of H:

The definition of Avogadro's number of 6.022 × 1023/mole is the number of atoms or molecules per one gram atomic weight. For one gram atomic weight of hydrogen with an atomic weight of one gram, one mole of hydrogen contains 6.022 × 1023 hydrogen atoms. 1.45⋅6.02⋅1023≈8.73⋅1023 hydrogen atoms.

1 mole:

The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. 12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms • The number of particles in 1 mole is called Avogadro's Number (6.0221421 x 1023).

in an H:

H: 2×2×4=16 atoms of hydrogen. C: It only appears once and without a subscript, so 1×4=4 .  O : Like carbon, it's 1×4=4 .

1.00 mole:

One mole is equal to 6.02214179×1023 atoms, or other elementary units such as molecules.

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Answer:

potassium I believe is the correct answer

Explanation:

Potassium is the period four element with the lowest mass; its average mass is 39.0983amu.

The fourth period of the periodic table is where potassium has its lowest atomic mass.

Atomic mass is defined as the combined mass of an atom's protons, neutrons, and electrons.  The term "atomic mass" refers to the weight of an atom or molecule. To determine the average mass of elements and molecules as well as to resolve stoichiometry issues, the atomic mass is used.

An electrically neutral atom has an equal number of protons and electrons. As a result, using any of the two formulas, we may calculate the atomic mass of an element. The atomic mass of an element grows as we move from left to right in a period of the periodic table. In the fourth period of the current periodic table, Krypton has the highest atomic mass and potassium has the lowest.

Thus, the fourth period of the periodic table is where potassium has its lowest atomic mass.

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solid.................

Answer:

b solid

Explanation:

i know for a fact