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3 years ago

What total energy (in kJ) is contained in 1.0 mol of photons, all with a frequency of 2.75*10^14 Hz

Chemistry

1 answer:

Murrr4er [49]3 years ago

5 0

Answer:

$1.1 \times 10^{5} J$

Explanation:

The computation is shown below:

Data provided in the question

The frequency of the radio wave is f = $2.75 \times 10^{14}\ Hz$

Let us assume the number of photons is N $= nNA = 1 \times 6.022 \times 10^{23}$

= $6.022 \times 10^{23}$

And, h = $6.626 \times 10{-34} J$

Based on the above information, the total energy is

As we know that

E = N h f

$= 6.022 \times 10^{23} \times 6.626 \times 10^{-34} \times 2.75 \times 10^{14}$

$= 1.1 \times 10^{5} J$

We just applied the above formula so that the total energy contained could come i.e by multiplying the three items so that the correct value could come

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"Write the electron Configuration expected for element 113 and the configurations for the two cations it is most likely to form"

arlik [135]

Answer:

Element:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶7s²5f¹⁴6d¹⁰7p¹

Cations:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶7s²5f¹⁴6d¹⁰

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶5f¹⁴6d¹⁰

Explanation:

The electron configuration is the distribution of the electrons in the sublevels in order of the crescent energy of them. The crescent energy of the sublevels follows the Linus Pauling's diagram, which is attached below. The sublevel "s" comports until 2 electrons, the sublevel "p" until 6 electrons, the sublevel "d" until 10 electrons, and sublevel "f" until 14 electrons.

So, for the element with an atomic number of 113, the neutral atom will have 113 electrons:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶7s²5f¹⁴6d¹⁰7p¹

Thus the element is at the 7 period (the highest level), and group 13 (most energic sublevel p with 1 electron), the group of the aluminum. It needs to lose 3 electrons to be stable and follow the octet rule, but the subshells of the last shell are too far away in energetic order, thus, it most probably to lose the electron of 7p and form a monovalent cation, and can lose the two electrons of 7s to form a trivalent cation:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶7s²5f¹⁴6d¹⁰

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶5f¹⁴6d¹⁰

5 0

3 years ago

Read the given expression. X = number of protons − number of core electrons Which of the following explains the identity of X an

shepuryov [24]

<u>Answer: </u>The correct statement is X is the effective nuclear charge, and it increases across a period.

<u>Explanation:</u>

We are given that:

X = number of protons − number of core electrons

Effective nuclear charge is defined as the actual nuclear charge (Z = number of protons) minus the screening effect caused by the electrons present between nucleus and valence electrons. These electrons are the core electrons.

The formula used for the calculation of effective nuclear charge given by Slater is:

$Z^*=Z-\sigma$

where,

$Z^*$ = effective nuclear charge

Z = atomic number or actual nuclear charge or number of protons

$\sigma$ = Screening constant

The effective nuclear charge increases as we go from left to right in a period because nuclear charge increases with no effective increase in screening constant.

Hence, the correct answer is X is the effective nuclear charge, and it increases across a period.

5 0

3 years ago

Which phrase is the best description of a topographic map? A shows the physical features of the land B shows political boundarie

Black_prince [1.1K]

A shows the physical features of the land

Explanation:

A topographic map is a map that shows the physical features of the land area. Rivers, streams, mountains, valleys, hills and other physical features.

A topographic map is made up of series of contour lines.
The contour lines are lines that joins places of equal elevation.
All places on the contour lines have the same elevation.
Using the contour lines, we can understand the landforms in an area.
Other map keys are used to delineate settlement patterns, streams, churches, dams and the like.
Most topographic maps are used as base maps for making other maps.

learn more:

Physical map brainly.com/question/3687554

#learnwithBrainly

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3 years ago

Read 2 more answers

In the titration of HCl with NaOH, the equivalence point is determined

kondaur [170]

Answer:

In the titration of HCl with NaOH, the equivalence point is determined from the point where the phenolphthalein turns pink and then remains pink on swirling.

Explanation:

The equivalence point is the point at which exactly enough titrant (NaOH) has been added to react with all of the analyte (HCl). Up to the equivalence point, the solution will be acidic because excess HCl remains in the flask.

Phenolphtalein is chosen because it changes color in a pH range between 8.3 – 10. Phenolphthalein is naturally colorless but turns pink in alkaline solutions. It remains colorless throughout the range of acidic pH levels, but it begins to turn pink at a pH level of 8.3 and continues to a bright purple in stronger alkalines.

It will appear pink in basic solutions and clear in acidic solutions.

The more NaOH added, the more pink it will be. (Until pH≈ 10)

In strongly basic solutions, phenolphthalein is converted to its In(OH)3− form, and its pink color undergoes a rather slow fading reaction and becomes completely colorless above 13.0 pH

a. from the point where the pink phenolphthalein turns colorless and then remains colorless on swirling.

⇒ the more colorless it turns, the more acid the solution. (More HCl than NaOH)

b. from the point where the phenolphthalein turns pink and then remains pink on swirling.

The equivalence point is the point where phenolphtalein turns pink and remains pink ( Between ph 8.3 and 10). (

Although, when there is hydrogen ions are in excess, the solution remains colorless. This begins slowely after ph= 10 and can be noticed around ph = 12-13

c. from the point where the pink phenolphthalein first turns colorless and then the pink reappears on swirling.

Phenolphthalein is colorless in acid solutions (HCl), and will only turn pink when adding a base like NaOH

d. from the point where the colorless phenolphthalein first turns pink and then disappears on swirling

Phenolphthalein is colorless in acid or neutral solutions. Once adding NaOH, the solution will turn pink. The point where the solution turns pink, and stays pink after swirling is called the equivalence point. When the pink color disappears on swirling, it means it's close to the equivalence point but not yet.

3 0

2 years ago

Show how the total charge sodium oxide is zero

coldgirl [10]

First, the symbol for sodium oxide is Na₂O

Each Na (sodium) has a charge of 1+, and each O has a charge of 2- :

Na₂¹⁺O²⁻

There are two Na's, however, and each one is 1+, however, so the Na₂ has a total charge of 2+. Because of this, the 2+ from the 2 Na's and the 2- from the O cancel each other out to make 0.

6 0

3 years ago