MCAT Physical assist » general Chemistry » Atoms, Elements, and also the routine Table » regular Trends

For any given chemistry reaction, one can draw an power diagram. Energy diagrams depict the energy levels of the different steps in a reaction, while also indicating the net change in energy and giving ideas to loved one reaction rate. 

Below, a reaction diagram is presented for a reaction the a scientist is examining in a lab. A student began the reaction the evening before, however the scientist is unsure regarding the form of the reaction. The cannot find the student’s notes, except for the reaction chart below.

You are watching: For which of the following elements will gaining an electron be the most exothermic process?

 

 

*


Using NMR, the scientist in the passage determines the there is a an adverse halide ion present in the assets when the reaction reaches action 5. I m sorry of the following determinants would have tendency to advanced the energy level at action 5?


Possible Answers:

Changing the halide from chloride to bromide


Changing the halide indigenous flouride to chloride


Changing the halide native bromide to flouride


Having the halide it is in bound come a cation


Changing the halide native flouride come iodide


Correct answer:

Changing the halide native bromide come flouride


Explanation:

If the halide was flouride, that would have a an unfavorable charge dispersed over a smaller cross sectional area than if that was any type of of the various other halides. Flouride is the smallest possible halide, and also thus has the greatest energy due to the fact that it concentrates an unfavorable charge on the the smallest area.


Report an Error

Example inquiry #1 : routine Trends


Place the following atoms in decreasing order of atom radius.

Cl, Ar, K, Ca


Possible Answers:

Ca, K, Cl, Ar


K, Ca, Cl, Ar


Cl, Ar, K, Ca


Ca, K, Ar, Cl


Correct answer:

K, Ca, Cl, Ar


Explanation:

Atomic radius has two basic trends which you should remember:

1. Atom radius will certainly decrease when relocating left to best along a period.

2. Atomic radius will increase when relocating down a group.

Since potassium (K) and also calcium (Ca) space farther under the team than argon (Ar) and also chlorine (Cl), us conclude the they are the largest atoms in the set. Since Ca is to the best of K, it is slightly smaller sized than K. Together a result, K has the largest atomic radius in the collection followed by Ca. Because Ar is come the appropriate of Cl, Cl has a bigger atomic radius 보다 Ar.

The decreasing bespeak is K, Ca, Cl, Ar.


Report an Error

Example concern #3 : periodic Trends


Which of the following aspects has the greatest reliable nuclear charge?


Possible Answers:

Chlorine


Bromine


Phosphorus


Sodium


Correct answer:

Chlorine


Explanation:

The reliable nuclear charge is the attractive fee a valence electron feels indigenous the nucleus. As you move from left to appropriate along a period, and an ext positive fees (protons) to fill up the nucleus, the much more attraction the valence electron feels. Together you move down a group, friend jump right into the following electron shell, therefore shielding the valence electrons from the inner hopeful charge, and decreasing the efficient nuclear charge.

Because chlorine is in the same duration as phosphorus and also sodium, but has the many protons in its covering (the most right within the exact same period) it has actually the greatest efficient nuclear charge. Additionally, since chlorine is in the same group as bromine, however is greater up top top the routine table, it has actually a greater efficient nuclear charge, making that the correct answer.


Report an Error

Example question #4 : periodic Trends


Rank the complying with ions in stimulate of decreasing atom radius.

*


Possible Answers:


*


*


*


*


Correct answer:


Explanation:

First, you have to see that all four of these ions have the same amount that electrons, causing a secure electron shell. These ions differ, however, through the number of protons in your nuclei. Due to the fact that the heavier ions have an ext protons pulling top top the exact same amount of electrons, the atomic radius will be smaller, as the an unfavorable electrons are attracted inward toward the optimistic nucleus.

Sr2+ has the many protons in that nucleus the end of this set, so it will have the the smallest atomic radius. The atomic radius will increase with decreasing atom number. 

The correct order from largest to smallest is Se2-, Br-, Rb+, and Sr2+.


Report an Error

Example concern #1 : regular Trends


Which of the provided atoms has the lowest electron affinity?


Possible Answers:

Ca


Be


Sr


Ra


Correct answer:

Ra


Explanation:

Beryllium, calcium, strontium, and also radium are all alkaline earth metals in the same group of the periodic table.

The electron affinity, a measure of the energy released as soon as an atom benefit an electron (an exothermic reaction), decreases indigenous the top of a team (column) come the bottom. The patterns in electron affinity can be correlated with ionization energy. When a smaller atom gains an electron, the force in between the electron and nucleus is greater than in a bigger atom; thus, an ext energy is released as soon as this “bond” in between the nucleus and electron is formed in a smaller sized atom than in a larger atom, an interpretation that smaller atoms will certainly have better electron affinity. Radium is the farthest under the group of alkaline planet metals, and will have actually the largest atomic radius the the answer choices, offering it the lowest electron affinity.


Report an Error

Example question #1 : routine Trends


Which of the provided atoms has actually the best electron affinity?


Possible Answers:

Cl


Na


P


Al


Correct answer:

Cl


Explanation:

Sodium, aluminum, phosphorus, and also chlorine space all in the exact same row (period) that the routine table.

The electron affinity, a measure up of the energy released as soon as an atom profit an electron (an exothermic reaction), boosts from left to right throughout the regular table because when a smaller sized atom gains an electron, the force between the electron and also nucleus is better than v a larger atom. An ext energy is released as soon as this “bond” in between the nucleus and electron is formed. Chlorine has the smallest atomic radius of the prize choices since it is situated farthest come the right of the period; thus, chlorine will additionally have the biggest attractive force between its nucleus and also electrons, providing it the highest electron affinity.


Report one Error

Example inquiry #2 : periodic Trends


Which element would experience the greatest energy loss once a neutral atom in the gaseous step gains one extr electron?


Possible Answers:

Cesium


Fluorine


Lithium


Chlorine


Krypton


Correct answer:

Fluorine


Explanation:

This concern refers come electron affinity, i beg your pardon is characterized as the energy given off as soon as a neutral atom in the gas phase gains an extra electron.

*

Electron affinity rises for elements towards the top and also right of the regular table, for this reason the aspects in the height right lose the most power when getting an electron. Another means of reasoning is that they lose energy, yet gain stability. That the available answers, the element to the many upper best of the routine table is fluorine.


Report one Error

Example concern #1 : Atoms, Elements, and The regular Table


Which aspect has the greatest electron affinity?


Possible Answers:

Oxygen


Fluorine


Magnesium


Carbon


Correct answer:

Fluorine


Explanation:

Electron affinity rises from left to right throughout a duration and indigenous bottom to height within a group in the periodic table. Electron affinity and also electronegativity are directly related. Fluorine is the many electronegative element, and also has a very very high electron affinity. Addition of an electron to fluorine completes the valence octet, offering stability.


Report an Error

Example concern #21 : periodic Trends


Atoms have actually characteristic electronegativities and also electron affinities. Which of the following best describes the difference between these two terms?


Possible Answers:

Electronegativity and also electron affinity space two state describing the very same atomic phenomenon


Depending top top the specific case, the electronegativity of one atom is figured out by that electron affinity


Electronegativity defines an atom"s propensity to retain its current electron configuration, if electron affinity explains an atom"s propensity to accept electrons


Electronegativity defines an atom"s tendency to accept electrons, while electron affinity explains an atom"s tendency to maintain its existing electron configuration


Electronegativity describes the potential one atom has to provide up that electrons, whereas electron affinity describes the potential an atom has actually to gain electrons


Correct answer:

Electronegativity explains an atom"s propensity to accept electrons, if electron affinity describes an atom"s tendency to maintain its present electron configuration


Explanation:

Electronegativity and also electron affinity deserve to be quickly confused. Both terms define resistance to electron gain, yet they do so by different classifications. Electronegativity describes how easily an atom will end up being an anion, or how easily it will certainly accept an electron. The halogens have incredibly high electronegativities, if the noble gases have virtually zero electronegativity. In contrast, electron affinity explains the energy adjust when one electron is added to one atom. The halogens, again, have an extremely high electron affinities. The noble gases will occasionally have negative electron affinities, indicating that it is an exothermic process to remove an electron from these elements.


Report one Error

Example concern #1 : routine Trends


Which of the complying with alkali metals has the greatest atomic radius?


Possible Answers:

Rubidium


Lithium


Sodium


Hydrogen


Correct answer:

Rubidium


Explanation:

The trend for atom radius is to increase going from top to bottom, as added valence shells are included to the atom. The end of the answer choices, rubidium has the highest energy valence shell.

*

With a solitary electron in the fifth energy level, krypton will have the highest variety of energy levels of the team I facets listed.

When moving throughout a period, atom radius will decrease as the number of protons increases. These protons rise the attraction between the high-energy electrons and the nucleus, efficiently "shrinking" the electron cloud.

See more: Franks European Service - Frank'S European Service


Report an Error
← vault 1 2 3 4 next →
see MCAT Chemical and Physical structures of biological Systems Tutors
Kathryn Certified tutor
Cornell University, Bachelor that Science, person Biology. Geisinger republic School of Medicine, doctor of Medicine, Biomed...
view MCAT Chemical and also Physical foundations of organic Systems Tutors
David Certified guardian
University that Florida, Bachelor the Science, Nutrition Sciences. University of Florida, doctor of Medicine, molecule Medicine.
view MCAT Chemical and Physical structures of organic Systems Tutors
Cameron Certified tutor
New York University, Bachelor in Arts, Biology, General.

All MCAT Physical resources


8 Diagnostic tests 303 exercise Tests concern of the day Flashcards discover by concept
Popular Subjects
SSAT Tutors in Denver, satellite Tutors in Phoenix, act Tutors in Los Angeles, GMAT Tutors in Dallas ft Worth, computer system Science Tutors in Boston, GMAT Tutors in Boston, MCAT Tutors in san Diego, computer system Science Tutors in new York City, computer Science Tutors in Seattle, mathematics Tutors in Boston
Popular courses & Classes
SSAT process & great in Houston, Spanish courses & great in Denver, SSAT process & classes in Los Angeles, MCAT courses & classes in new York City, ISEE process & class in Houston, LSAT process & great in Dallas ft Worth, SSAT process & class in Chicago, GRE process & classes in Washington DC, GMAT process & classes in Washington DC, ISEE process & class in Seattle
Popular test Prep
sat Test prepare in Seattle, LSAT check Prep in Dallas fort Worth, GMAT test Prep in Atlanta, GMAT test Prep in Washington DC, MCAT test Prep in Los Angeles, MCAT test Prep in Miami, GRE test Prep in Miami, SSAT check Prep in Houston, satellite Test prepare in Washington DC, LSAT test Prep in Phoenix
Report an worry with this question

If you"ve found an issue with this question, please let us know. V the aid of the community we can continue to improve our educational resources.


Do no fill in this field
* your Name:
* problem Description:
DMCA complain

your Infringement notice may be forwarded come the party that made the content easily accessible or to third parties such as ChillingEffects.org.

you re welcome follow these actions to paper a notice:

you must include the following:

Send your complain to our designated agent at:

Charles Cohn Varsity Tutors gmbh 101 S. Hanley Rd, Suite 300 St. Louis, MO 63105