Chem test

Ions of an unknown element are run through a mass spectrometer producing the results show below.

Isotope Data

Based on this data,

a) find the atomic mass

AND

b) identify the element.

Show ALL work.

Element [math]\mathrm{X}[/math] occurs naturally in the environment. Scientists have found 612 atoms of [math]^{25}\text{X}[/math], 729 atoms of [math]^{26}\text{X}[/math], and 344 atoms of [math]^{27}\text{X}[/math].
Actual masses of isotopes:
[math]^{25}\text{X} = 24.9476[/math]
[math]^{26}\text{X} = 25.9477[/math]
[math]^{27}\text{X} = 26.9479[/math]
(a) Calculate the percent abundance of each isotope.(b) Calculate the average atomic mass of element X.

The graph below shows the relative abundance of the isotopes of some element as measured by a mass spectrometer. It displays the number of isotopes of a specific element relative to others.

(a) Calculate the percent abundance of each isotope.(b) Calculate the atomic weight of the unknown element.(c) Identify the unknown element.

Copper has two naturally occurring isotopes. One of those isotopes, [math]^{63}\text{Cu}[/math], has an atomic mass of [math]62.9296[/math] amu and an abundance of [math]69.15\%[/math].(a) If the average atomic mass of Cu is 63.546, what us the atomic mass of the second isotope?(b) How many neutrons are in the second isotope?

The Mass Spectrum of unknown element X is listed below:

(a) Based on the data above, calculate the average atomic mass of the unknown element X.

(b) Identify the unknown element X.

A certain element (X) has three common isotopes: [math]^{28}\text{X}[/math] (isotopic mass of [math]27.977[/math] amu), [math]^{29}\text{X}[/math] ([math]28.976[/math] amu), and [math]^{30}\text{X}[/math] ([math]29.974[/math] amu).
[math]^{28}\text{X}[/math] has a natural abundance of [math]92.22\%[/math].
[math]^{29}\text{X}[/math] has a natural abundance of [math]4.68\%[/math].(a) What is the natural abundance of X-30?(b) Calculate the average atomic mass of element X.(c) Identify element X.

An unknown sample of an element X is analyzed by mass spectroscopy.
The mass spectrum shows 2 isotopes, [math]^{35}\text{X}[/math] with a mass of [math]34.97[/math] amu and [math]72.76\%[/math] abundance, and [math]^{37}\text{X}[/math] with a mass of [math]36.97[/math] amu and [math]27.24\%[/math] abundance.
(a) Using this data, calculate the average atomic mass of element X.(b) Based on the average atomic mass you calculated, suggest the most likely element for X.

An unknown sample of an element X is analyzed by mass spectroscopy.
The mass spectrum shows 2 isotopes, [math]^{35}\text{X}[/math] with a mass of [math]34.97[/math] amu and [math]72.76\%[/math] abundance, and [math]^{37}\text{X}[/math] with a mass of [math]36.97[/math] amu and [math]27.24\%[/math] abundance.
After looking at your data more closely, you realized that you were only able to detect 95% of the atoms that you sent through the mass spectrometer. It looks like the detector wasn t able to count some of the isotopes! Discuss what effect, if any, this could have on your calculations of the average atomic mass. Be specific about whether the mass will change, and in which direction.

Ant-Man shrunk down to an atomic size to help take the mass spectrum of an element sample by hand. The sample contained exactly 350 atoms. He couldn t tell what element it was, but he was able to lift each atom up and determine how heavy it was. He found that the atoms had three different masses, despite all having the same number of protons. One group of 60 atoms weighted 87.0 amu each, the second group of 113 atoms weighed 88.0 amu each, and the last group of 177 atoms weighed 90.0 amu each.(a) Calculate the percent abundance of each isotope in this element.
(b) Calculate the average mass for this element sample.(c) Identify the unknown element from the sample.

Ant-Man shrunk down to an atomic size to help take the mass spectrum of an element sample by hand. The sample contained exactly 350 atoms. He couldn t tell what element it was, but he was able to lift each atom up and determine how heavy it was. He found that the atoms had three different masses, despite all having the same number of protons. One group of 60 atoms weighted 87.0 amu each, the second group of 113 atoms weighed 88.0 amu each, and the last group of 177 atoms weighed 90.0 amu each.
d) The average mass you calculated should be slightly off from the accepted
e) Sketch a mass spectrum for the element, including all elements of a good graph.

Photons of ultraviolet light possess enough energy to mutate a strand of human DNA. What is the energy (E) of a UV photon having a wavelength of 25 nm? Show ALL work. (bonus: how about 1 mole of photons?)

A single photon of ultraviolet light possesses enough energy to mutate a strand of human DNA.
A single photon is equivalent to [math]7.93 \times 10^{-21}[/math] kJ of energy. Identify the wavelength of a UV photon.

You are trying to ionize an unknown atom by removing an electron from it. You find that it takes a photon with an energy of [math]8.42 \times 10^{-19}[/math] J to ionize the atom.
(a) What wavelength (in nm) of light corresponds to photons with that much energy?(b) You have successfully removed an electron from the atom! If you want to remove another electron, will you need to use light with a longer wavelength, a shorter wavelength, or the same wavelength?

You are trying to ionize an unknown atom by removing an electron from it. You find that it takes a photon with an energy of [math]8.42 \times 10^{-19}[/math] J to ionize the atom.
a) What wavelength (in nm) of light corresponds to photons with that much energy?
b) You have successfully removed an electron from the atom! If you want to remove another electron, will you need to use light with a longer wavelength, a shorter wavelength, or the same wavelength? [math]\textbf{Explain your answer.}[/math]

The line spectrum for hydrogen is given. Determine whether the statement is true or false. Explain your choices.
Each line represents a possible energy level that hydrogen s electron may be found in.

The line spectrum for hydrogen is given. Determine whether the statement is true or false. Explain your choices.
There is no orange or green line because electrons can only exist in specific energy levels.

The line spectrum for hydrogen is given. Determine whether the statement is true or false. Explain your choices.
Hydrogen s most common ion, [math]\mathrm{H}^+[/math], has the same line spectrum as hydrogen.

The line spectrum for hydrogen is given. Determine whether the statement is true or false. Explain your choices.
There are more than four possible transitions between energy levels for the hydrogen atom.

The wavelength of the red light is longer than the wavelength of the blue light because it comes from an electron traveling a longer distance.

The bright line emission spectrum for an atom is shown here.

Briefly explain what determines whether or not you see a line in a certain spot in the visible part of the emission spectrum. Why are there lines in some places, but not others?

The bright line emission spectrum for an atom is shown here.

What color would you expect a lamp make with this element to appear to be? Explain. (You don t need to get an exact color, but explain your thinking.)

The bright line emission spectrum for an atom is shown here.

Would there be any changes to this spectrum if you [math]\textbf{change the number of protons}[/math] for the atom. (yes/no)
Why?

The bright line emission spectrum for an atom is shown here.

Would there be any changes to this spectrum if you [math]\textbf{change the number of neutrons}[/math] for the atom. (yes/no)
Why?

The bright line emission spectrum for an atom is shown here.

Would there be any changes to this spectrum if you [math]\textbf{create an ion by adding an electron}[/math] to the atom. (yes/no)
Why?

The line spectrum for oxygen ([math]\mathrm{O}[/math], #8) is given below. For he claim below, state whether they are true or false. If it is true, provide a supporting explanation. If it is false, provide a correction to the statement or an explanation of why the statement is incorrect.

The color of a line matches the energy of an orbital that an electron can be in.

The line spectrum for oxygen ([math]\mathrm{O}[/math], #8) is given below. For he claim below, state whether they are true or false. If it is true, provide a supporting explanation. If it is false, provide a correction to the statement or an explanation of why the statement is incorrect.

There is no lines in between green and blue because electrons can only exist in specific energy levels.

The line spectrum for oxygen ([math]\mathrm{O}[/math], #8) is given below. For he claim below, state whether they are true or false. If it is true, provide a supporting explanation. If it is false, provide a correction to the statement or an explanation of why the statement is incorrect.

The wavelength of the red light is longer than the wavelength of the green light because electrons fall a further distance when releasing red light compared to green light.

The line spectrum for oxygen ([math]\mathrm{O}[/math], #8) is given below. For he claim below, state whether they are true or false. If it is true, provide a supporting explanation. If it is false, provide a correction to the statement or an explanation of why the statement is incorrect.

Although [math]\mathrm{Ne}^{2+}[/math] has the same number of electrons as oxygen, it will have a different line spectrum.

Identify which of the following 5 electron configurations represent each statement.
Briefly explain how you arrived at each of your choice.
(Hint: there may be multiple correct answers for each statement. Include all correct answers).
(A) [math]\mathrm{Li}: 1s^22p^1[/math]
(B) [math]\mathrm{C}^+: 1s^22s^22d^1[/math]
(C) [math]\mathrm{H}^-: 1s^2[/math]
(D) [math]\mathrm{He}: 1p^1[/math]
(E) [math]\mathrm{O}^+: 1s^22s^22p^3[/math](a) A ground-state configuration(b) An electron configuration of an excited state(c) An impossible electron configuration

Identify which of the following electron configurations represent each statement.
Explain how you arrived at each of your choices.
(FYI: there may be multiple correct answers for each statement. Include all correct answers).
(A) [math]\mathrm{B} : 1s^2\, 2s^2\, 3s^1[/math]
(B) [math]\mathrm{N}^+ : 1s^2\, 2s^2\, 2d^2[/math]
(C) [math]\mathrm{He}^+ : 1s^1[/math]
(D) [math]\mathrm{H} : 1p^1[/math]
(E) [math]\mathrm{O}^- : 1s^2\, 2s^2\, 2p^5[/math]

(a) a ground-state electron configuration (b) an electron configuration of an excited state (c) an impossible electron configuration

Write the ground state electron configuration for [math]\mathrm{Ni}^{2+}[/math].

Identify two ions from different energy levels that are isoelectronic with the element Argon.
Place these isoelectronic species in increasing size, and briefly explain the order you choose.

Which of the following is the correct ground state electron configuration of phosphorous, P? What is wrong with each of the others?

\[
\begin{array}{l c c c c}
\mathrm{[Ne]} & [\uparrow\:\uparrow\:] & [\uparrow\quad] & [\uparrow\quad] & [\uparrow\quad] \\
& 3s &&{3p} \\
\\
\mathrm{[Ne]} & [\uparrow\:\downarrow\:] & [\uparrow\quad] & [\uparrow\quad] & [\uparrow\quad] \\
& 3s &&{3p} \\
\\
\mathrm{[Ne]} & [\uparrow\:\downarrow\:] & [\uparrow\:\downarrow\:] & [\uparrow\quad] & [\quad\;] \\
& 3s &&{3p} \\
\end{array}
\]

This question is about the electron configuration for Gd (Gadolinium, #64)

a) Draw the expected abbreviated (noble gas) orbital box diagram for the ground state of [math]\mathrm{Gd}[/math].
b) According to your electron configuration, how many valence electrons does [math]\mathrm{Gd}[/math] have?
c) [math]\mathrm{Gd}[/math] s actual ground state electron configuration is [math][\mathrm{Xe}]\, 6s^2\, 4f^7\, 5d^1[/math]. Using an appropriate orbital box diagram, suggest why [math]\mathrm{Gd}[/math] has this electron configuration, instead of the expected one.
d) [math]\mathrm{Gd}[/math] tends to form 2 common ions: [math]\mathrm{Gd}^{2+}[/math] and [math]\mathrm{Gd}^{3+}[/math]. Suggest why these ions of [math]\mathrm{Gd}[/math] are the most common, and others are harder to form.

Complete the nuclear reaction equation below with a correct atomic symbol.

Complete the nuclear reaction equation below with a correct atomic symbol.

Complete the nuclear reaction equation below with a correct atomic symbol.

Suppose that a stable element with atomic number 120, symbol Q, has been discovered.(a) Write the ground-state electron configuration for Q, using the shortcut method.(b) Would Q be a metal or a nonmetal?(c) On the basis of periodic trends, how would the atomic radius of Q compare to that of Radium (Ra)?(d) What would likely be the charge of the Q ion?

Identify which, if any, physical properties listed below represent differences between a [math]\mathrm{Ca}^{2+}[/math] ion and a [math]\mathrm{Ca}[/math] atom. Briefly explain the cause for these differences.(a) number of valence electrons(b) atomic mass(c) nuclear charge(d) GOGO(e) GOGO

Explain the following statement:
Potassium has a lower first-ionization energy than lithium.

Explain the following statement:
The ionic radius of [math]\mathrm{N}^{3-}[/math] is larger than that of [math]\mathrm{O}^{2-}[/math].

Explain the difference between [math]\mathrm{Mg}[/math] and [math]\mathrm{Na}[/math] in regard to their first ionization energies ([math]\mathrm{Mg} = 737[/math], [math]\mathrm{Na} = 496[/math])

Explain the difference between [math]\mathrm{Mg}[/math] and [math]\mathrm{Na}[/math] in regard to their second ionization energies ([math]\mathrm{Mg} = 1450[/math], [math]\mathrm{Na} = 4563[/math])

Explain each of the following ionization energy trend:
The first ionization energy for magnesium is greater than the first ionization energy for calcium

Explain each of the following ionization energy trend:
The first and second ionization energies for calcium have a small difference is energy, but the first and second ionization energies for potassium have a large difference in energy.

Explain each of the following ionization energy trend:
The first ionization energy for sulfur is lower than the first ionization energy for phosphorous.

Consider N and O.
By general principal of periodic trend, which atom should have the larger radius.?

Draw the orbital box diagrams for the valence shell of N and O to help you to answer the following:
Oxygen has a lower first ionization energy than nitrogen. Explain why this is consider an “EXCEPTION” of general peciodic trend, and why that happens using the orbital box diagram you drew.

Draw the orbital box diagrams for the valence shell of N and O to help you to answer the following:
Having data for successive ionization energies (I1, I2, I3 etc. ) for an atom allows one to predict how many valence electrons the atom possesses. Using either oxygen or nitrogen, explain how this is done.

(I have a graph)Explain why nitrogen has a higher first ionization energy than carbon.

(I have a graph)Explain why magnesium has a lower first ionization energy than beryllium.

(I have a graph)Explain why the second ionization energy for fluorine is larger than the first ionization energy for fluorine.

Ionization Energies (kJ/mol)

Which element(s) is /are likely non-metals? Explain.

Ionization Energies (kJ/mol)

Which element(s) commonly forms a +2 charge when it becomes an ion? Explain.

Ionization Energies (kJ/mol)

If element D combines with nitrogen, what is the combining ratio (formula of the compound)? Explain.

Ionization Energies (kJ/mol)

Which element is MOST likely to be a noble gas? Explain.

Ionization Energies (kJ/mol)

Which unknown element might be a non-metal? Briefly explain your choice.

Ionization Energies (kJ/mol)

Which unknown element(s) have an oxidation state of 2+? Briefly explain your choice(s).

Ionization Energies (kJ/mol)

If unknown element D were to bond with [math]^{16}\mathrm{S}[/math], what would be the combining ratio? Briefly explain how you arrived at your answer.

Ionization Energies (kJ/mol)

If unknown element B were to bond with oxygen, what would be the expected chemical formula? Briefly explain how you arrived at your answer.

Ionization Energies (kJ/mol)

Which unknown element(s) might be a non-metal? Briefly explain your choice(s).

Ionization Energies (kJ/mol)

Which unknown element(s) have 3 valence electrons? Briefly explain your choice(s).

Ionization Energies (kJ/mol)

If unknown element B were to bond with oxygen, what would be the expected chemical formula? Briefly explain how you arrived at your answer.

Of all elements on the periodic table, francium (#87) has the least attraction of its valence electrons to its nucleus. Provide two reasons and explanations as to why this statement is correct.

Provide justification for the specific order you come up with.
[math]\mathrm{S}^{2-}, \mathrm{Na}^+, \mathrm{Ne}, \mathrm{O}^{2-}, \mathrm{Mg}^{2+}[/math]

Which has a higher ionization energy: [math]_{37}\mathrm{Rb} [/math] or [math]_{38}\mathrm{Sr}[/math]? Explain.

Which has a higher ionization energy: [math]_{37}\mathrm{Rb} [/math] or [math]_{38}\mathrm{Sr}[/math]? Explain.

Which has a higher [math] \textbf{second ionization energy}[/math]: [math]_{37}\mathrm{Rb} [/math]or [math]_{38}\mathrm{Sr}[/math? Explain.

Consider Mg and Al.
Based on the expected trend, explain why Al has a higher electronegativity than Mg.

Draw the orbital box diagrams for the valence shell of Mg and Al to help you to answer the following:
Al has a [math]\textbf{lower}[/math] first ionization energy than Mg. Explain why this doesn t match the general periodic trend, and suggest why this happens using the orbital box diagram you drew.

Having data for successive ionization energies (IE1, IE2, IE3 etc.) for an atom allows one to predict how many valence electrons the atom possesses. Using either Mg or Al (your choice!) as an example, explain how this is done.
Be clear about what you are looking for and why you will see it.

Consider the ions [math]\mathrm{Mg}^{2+} [/math]and [math]\mathrm{Al}^{3+}[/math], and the neutral atoms [math]\mathrm{Ne}[/math] and [math]\mathrm{Ar}[/math].
Sort all four by increasing radius. Explain how you reach your answer.

As you go across the third period (third row) form left to right, the ionization energy increases and the number of valance electron increases. Is the statement above true or flase?

As you go across the third period (third row) form left to right, the ionization energy increases and the number of valance electron increases. Explain.

As you go across the third period (third row) form left to right, the ionization energy increases because the number of valence electrons increases. Is this statement true of false?

As you go across the third period (third row) form left to right, the ionization energy increases because the number of valence electrons increases. Explain if this is true or false.

[math]\mathrm{Ar},\ \mathrm{Br^-},\ \mathrm{Ca^{2+}},\ \mathrm{Cl^-}[/math]
Rank the ion/atom from [math]\textbf{smallest to largest}[/math] radius.
Explain your reasoning for your order. In your explanation, make sure you discuss each atom/ion at least once. While it is not mandatory for all four, you should consider and/or write down the number of protons and the electron configurations for each atom/ion.

The common charge for a specific ion can be determined by analyzing the attractive and repulsive forces within the atom. In this exercise, you’ll analyze aluminum (Al, #13) in order to determine why the likely charge on its ion is +3.
You may write the (full) electron configurations for [math] \mathrm{Al, Al^+, Al^{2+}, Al^{3+}}[/math] to help you to answer the following:

(a) Calculate the effective nuclear charge on each of the four atoms/ions

(b) Which ion is the most likely ion that aluminum forms? Use your calculation as a reference.

Explain why [math]\mathrm{Al^{3+}}[/math] is the most common ion to form compare with [math]\mathrm{Al^+}[/math] and [math]\mathrm{Al^{2+}}[/math]

An unknown element, X, has five valence electrons.
If you looked at successive ionization energies for element X, what pattern would you expect from the 1st to the 6th?

An unknown element, X, has five valence electrons.
Element Y, which is directly to the right of element X on the periodic table, has a lower 1st ionization energy than element X. Explain why that is.

In terms of the four properties shown below, identify and explain the differences or similarities between [math]^{49}\mathrm{In}[/math] and [math]^{38}\mathrm{Sr}[/math].(a) Number of valence electrons(b) Nuclear charge (Z)(c) Effective nuclear charge (Zeff)(d) Size

Silicon has four valence electrons.
Would silicon have a larger or smaller radius than a radium atom?

Silicon has four valence electrons.
Would silicon have more or less electron affinity than oxygen?

Silicon has four valence electrons.
If you looked at successive ionization energies for silicon, what pattern would you expect from the 1st to the 6th?

Silicon has four valence electrons.
How would you expect the first ionization energy of silicon to compare to the first ionization energy for aluminum?