Search found 68 matches
- Fri Mar 16, 2018 12:21 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 8.77
- Replies: 1
- Views: 354
8.77
can someone explain in simple terms what this is asking for and how i would use resonance to solve it
- Thu Mar 15, 2018 11:37 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 8.65
- Replies: 1
- Views: 349
8.65
why don't we account for the hf of oxygen in the end reaction?
- Thu Mar 15, 2018 11:37 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: H+
- Replies: 3
- Views: 595
Re: H+
I was wondering the same thing.
- Mon Mar 12, 2018 10:47 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3617977
Re: Post All Chemistry Jokes Here
Did you know protons have mass?
I didn't even know they were Catholic!
I didn't even know they were Catholic!
- Mon Mar 12, 2018 10:45 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3617977
Re: Post All Chemistry Jokes Here
Money Has Recently Been Discovered To Be A Not Yet Identified Super Heavy Element
The proposed name is: Unobtainium.
The proposed name is: Unobtainium.
- Mon Mar 12, 2018 10:44 am
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL
- Replies: 9
- Views: 1434
Re: FINAL
Everything on the syllabus will be on the final ( so yes everything but 15.9).
- Mon Mar 12, 2018 10:27 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: K
- Replies: 7
- Views: 880
Re: K
I believe K is only affected by change in energy (heat) and activation energy.
Hope this helps :))))))
Hope this helps :))))))
- Mon Mar 12, 2018 10:24 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Rate-determining slowest step
- Replies: 5
- Views: 1190
Re: Rate-determining slowest step
I believe that will always be given in the problem (whether explicitly states in directions, or derived from the rates given). Hope this helps :)
- Mon Mar 12, 2018 10:20 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Intermediates
- Replies: 6
- Views: 772
Re: Intermediates
Yes, any substance that is cancelled out and not in the final reaction is an intermediate (whether it appears a product or reactant first).
- Mon Mar 12, 2018 10:15 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 6
- Views: 810
Re: Cell Diagrams
Anode is always listed first.
- Mon Mar 12, 2018 10:14 am
- Forum: Balancing Redox Reactions
- Topic: Reducing Power
- Replies: 2
- Views: 426
Re: Reducing Power
Like in the test, you will be given the standard reduction potentials and you must judge from there. For context: The more positive the potential is the more likely it will be reduced. (So it's the oxidizing agent because it has higher oxidizing power) So using deductive reasoning, the more negative...
- Mon Mar 12, 2018 10:11 am
- Forum: Balancing Redox Reactions
- Topic: Oxidation Number
- Replies: 4
- Views: 543
Re: Oxidation Number
The overall charge of a molecule is the number charged to it and the end (if there's nothing there, set the charge equal to zero). Then we would use set oxidation values (O = -2, H= 1) and add it to X (or times it by a coefficient) of the oxidation charge we DON't know. Then we set that to the overa...
- Mon Mar 12, 2018 10:07 am
- Forum: Balancing Redox Reactions
- Topic: Ranking elements
- Replies: 8
- Views: 1186
Re: Ranking elements
Like in the test, you will be given the standard reduction potentials and you must judge from there. For context: The more positive the potential is the more likely it will be reduced. So using deductive reasoning, the more negative the potential, the less likely it will be reduced (and more likely ...
- Mon Mar 12, 2018 10:04 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open, closed, or isolated test 1 question
- Replies: 10
- Views: 1655
Re: Open, closed, or isolated test 1 question
It's an open system
- Mon Mar 12, 2018 10:02 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed vs isolated
- Replies: 11
- Views: 1380
Re: closed vs isolated
No, unless the problem specifies. When given just "closed" or "isolated" that deals with energy exchange (or lack thereof).
- Mon Mar 12, 2018 10:00 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Work
- Replies: 6
- Views: 977
Re: Work
Work does not occur in a vacuum, so no I think.
- Mon Mar 12, 2018 9:58 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: The First Law
- Replies: 6
- Views: 983
Re: The First Law
Yes, they are the same. Just remember deltau=q+w.
- Mon Mar 12, 2018 9:56 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: What does R stand for?
- Replies: 13
- Views: 3389
Re: What does R stand for?
The ideal gas constant! Like everyone said, make sure to look at the equations sheet and look at the right units to use for numbers in a particular problem.
- Mon Mar 12, 2018 9:54 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Heat capacity question
- Replies: 5
- Views: 729
Re: Heat capacity question
R refers to the gas constant.
- Mon Mar 12, 2018 9:51 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Heat Required to Heat a Substance
- Replies: 5
- Views: 699
Re: Heat Required to Heat a Substance
The problem deals with molecular complexity regarding heat capacities. Heat capacities are always higher for more complex molecules because it takes more energy to break more bonds/etc. In this particular problem, we can see butane contains much more molecular complexity than H2, who only has one bo...
- Mon Mar 12, 2018 9:47 am
- Forum: Phase Changes & Related Calculations
- Topic: The universe
- Replies: 9
- Views: 1112
Re: The universe
As of now, the universe is the ultimate surrounding that contains everything. So there is nothing outside to exchange with.
- Mon Mar 12, 2018 9:46 am
- Forum: Phase Changes & Related Calculations
- Topic: calculating a phase change in a reaction
- Replies: 5
- Views: 785
Re: calculating a phase change in a reaction
You should always account for phase changes for "calculating heat" problems because there's an energy change between phases we need to account for in the ultimate result.
- Mon Mar 12, 2018 9:44 am
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic/exothermic
- Replies: 4
- Views: 1218
Re: Endothermic/exothermic
You would use common knowledge to understand if something is heating up or not. And using that, we can determine if something is endothermic (takes heat), or exothermic (loses heat) in regards to each term in a reaction.
- Mon Mar 12, 2018 9:43 am
- Forum: Phase Changes & Related Calculations
- Topic: Environmental impact?
- Replies: 6
- Views: 1032
Re: Environmental impact?
It would probably just include the environmental impact (surroundings and such) as context for a problem, but I doubt we would need to memorize how to deal with a complex problem dealing specifically in it.
- Mon Mar 12, 2018 9:41 am
- Forum: Phase Changes & Related Calculations
- Topic: Specific heat of water or ice?
- Replies: 6
- Views: 1120
Re: Specific heat of water or ice?
We would use specific heat of ice when H20 is presented in the problem as a solid and undergoing a fusion reaction in the reaction, and use specific heat of water when H20 is being presented in the problem as a liquid.
- Mon Mar 12, 2018 9:38 am
- Forum: Phase Changes & Related Calculations
- Topic: Exothermic Reaction
- Replies: 3
- Views: 435
Re: Exothermic Reaction
The heat (energy) is being used to break or form bonds for phase changes instead of changing the temperature of the reaction. In addition, as Lavelle said in class: " If the system (reaction) is small compared to the surroundings then the temperature of the surroundings does not change. Tonight...
- Thu Mar 01, 2018 5:27 pm
- Forum: First Order Reactions
- Topic: 15.29 b
- Replies: 1
- Views: 240
15.29 b
I got part a of this question without using the answer solution method by simple logistics (A decreases at 1/3 rate of B because of coefficients so subtract that from initial A) but part b requires we use that method and I don't understand it. Why do we substract (1molA/2molB) in the first place for...
- Fri Feb 16, 2018 3:53 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3617977
Re: Post All Chemistry Jokes Here
NUMBER 5 ON THE MID TERM AMIRITE LADIES??
- Tue Feb 13, 2018 11:27 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Test 1 Question 1c
- Replies: 3
- Views: 396
Re: Test 1 Question 1c
My bad, misread my own handwriting.
- Tue Feb 13, 2018 11:23 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Example 9.16
- Replies: 1
- Views: 103
Example 9.16
For the first part of the question, do we not calculate the standard formation change in enthalpy of Fe and C because they're pure elements?
- Tue Feb 13, 2018 1:25 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Reversible vs Irreverisble
- Replies: 1
- Views: 300
Reversible vs Irreverisble
Hi, I was wondering on the mid term/future exams, would the problem state if a certain process is reversible or irreversible? I understand that to be reversible you have to ; the temperature of system and surroundings have to be small change and constant but what does that mean realistically and how...
- Mon Feb 12, 2018 9:51 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Test 1 Question 1c
- Replies: 3
- Views: 396
Test 1 Question 1c
Hi, for "Do you expect there to be a difference between your answer in part (a) and part (b)? " I put that there is an expected difference because mean bond enthalpies are more accurate than ΔHf ways. I got the question right but shouldn't it be the other way around because it's a MEAN bon...
- Mon Feb 12, 2018 12:54 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Equipartition Theorem
- Replies: 1
- Views: 367
Equipartition Theorem
Hi could someone please explain in simple terms the equipartition theorem and how we would use it in calculations..
THank you
THank you
- Mon Feb 12, 2018 12:25 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Cp vs Cv
- Replies: 1
- Views: 204
Cp vs Cv
Hi, I understand that The heat capacity at constant pressure is greater than that at constant volume because at constant pressure not all the heat supplied is used to raise the temperature: some returns to the surroundings as expan- sion work and C q/ T is larger (because T is smaller) than at const...
- Sat Feb 10, 2018 7:08 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: tested: gibbs free energy derivation?
- Replies: 1
- Views: 371
tested: gibbs free energy derivation?
Hi, I understand that it's important to understand the derivations and how we find a quantitave relation between the Gibbs free energy and the maximum non expansion work that a system can do.. I remember that Professor Lavelle went over this in class but I don't remember him saying we were going to ...
- Sat Feb 10, 2018 6:11 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Explain Figure 9.25...
- Replies: 1
- Views: 290
Explain Figure 9.25...
Hi, I'm very confused by what Figure 9.25 in the textbook is trying to tell us.
And the attached paragraph is really confusing and convoluted..
Would anyone be able to summarize the information the graph is trying to tell in regards to Gibbs free energy and phase changes??
And the attached paragraph is really confusing and convoluted..
Would anyone be able to summarize the information the graph is trying to tell in regards to Gibbs free energy and phase changes??
- Sun Feb 04, 2018 6:17 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 9.19
- Replies: 2
- Views: 294
9.19
Can someone explain to me why, when you cool the water back down, you use Cp (constant pressure)? Instead of standard heat capacity..
- Sun Feb 04, 2018 5:24 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: conceptual question about change in entropy due to both temp and vol [ENDORSED]
- Replies: 3
- Views: 432
conceptual question about change in entropy due to both temp and vol [ENDORSED]
I understand that it's a 2 step process that we end up adding all together. But why do we use constant volume for the temperature equation? The volume is changing, so how is it heat capacity at constant volume?
- Wed Jan 31, 2018 11:09 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: 9.5
- Replies: 5
- Views: 610
9.5
Why is q/t for 800 K negative but q/t for 200k is positive?
- Mon Jan 22, 2018 12:40 am
- Forum: Phase Changes & Related Calculations
- Topic: ΔU vs. ΔH
- Replies: 10
- Views: 3640
Re: ΔU vs. ΔH
Delta H deals with internal energy at a constant pressure versus delta U is just change in internal energy.
- Tue Jan 16, 2018 11:06 pm
- Forum: Calculating Work of Expansion
- Topic: 8.3b
- Replies: 3
- Views: 313
Re: 8.3b
@Hannah
so then please explain why for 8.11 the more negative work answer "does more work"...
so then please explain why for 8.11 the more negative work answer "does more work"...
- Tue Jan 16, 2018 5:25 pm
- Forum: Calculating Work of Expansion
- Topic: 8.3b
- Replies: 3
- Views: 313
8.3b
Hi could someone please explain why for question 8.3 b (which asks if the work with respect to air in the pump is positive or negative) the answer is positive?
If the work is positive because you need more work to compress air (not sure if this is why), in which instances would work be negative?
If the work is positive because you need more work to compress air (not sure if this is why), in which instances would work be negative?
- Sun Jan 14, 2018 6:29 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3617977
Re: Post All Chemistry Jokes Here
i love chemicals
- Sun Jan 14, 2018 1:52 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Not a State Property
- Replies: 6
- Views: 537
Re: Heat Not a State Property
State properties depend solely on final and initial states but heat depends on the path taken.
- Sat Jan 13, 2018 7:59 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: When considering enthalpy (Δ H=q), is the letter "H" or "ΔH" Enthalpy?
- Replies: 3
- Views: 436
Re: When considering enthalpy (Δ H=q), is the letter "H" or "ΔH" Enthalpy?
H is enthalpy, and DeltaH is simply the change in enthalpy. However, we are interested in DeltaH because that is how we can measure the change in temperature (and subsequently, internal energy) because a change in the enthalpy of a system is equal to the heat released or absorbed at constant pressure.
- Mon Jan 08, 2018 10:52 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: lecture-exothermic reactions with constant temperature? [ENDORSED]
- Replies: 1
- Views: 168
lecture-exothermic reactions with constant temperature? [ENDORSED]
Lavelle mentioned this in lecture but I'm still confused.
How can exothermic reactions be a reaction with constant temperature?
How can exothermic reactions be a reaction with constant temperature?
- Sat Dec 09, 2017 8:30 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Question 12.45
- Replies: 3
- Views: 702
Re: Question 12.45
The smaller the pKB, the stronger the base is.
- Sat Dec 09, 2017 7:00 pm
- Forum: Empirical & Molecular Formulas
- Topic: empirical vs theoretical vs derived relationship/formula
- Replies: 1
- Views: 872
empirical vs theoretical vs derived relationship/formula
Sorry this might be in the completely wrong category. In chemistry, what is the difference between an "empirical" relationship and a "theoretical" relationship. And how do you determine if a formula was derived or not. Like conceptually. I just noticed this on a past final questi...
- Sat Dec 09, 2017 3:15 pm
- Forum: Conjugate Acids & Bases
- Topic: 12.35
- Replies: 1
- Views: 309
Re: 12.35
The smaller the Pka, the stronger the acid. But the larger the Ka itself, means it's a stronger acid. (This can be seen in the relationship pka=-log[ka].
- Fri Dec 08, 2017 2:17 pm
- Forum: Ionic & Covalent Bonds
- Topic: Memorization of Electronegativity
- Replies: 6
- Views: 988
Re: Memorization of Electronegativity
Knowing the basic trends is enough. But remember the exception with noble gases too. Like Lavelle said, the only chart we need to memorize is the ligands chart!:)
- Fri Dec 08, 2017 5:18 am
- Forum: Lewis Acids & Bases
- Topic: Will titrations be on test?
- Replies: 2
- Views: 454
Re: Will titrations be on test?
No. Titrations and Salts will not be covered on the final.
- Fri Dec 08, 2017 5:12 am
- Forum: Naming
- Topic: What is delocalized bonding? [ENDORSED]
- Replies: 5
- Views: 1175
What is delocalized bonding? [ENDORSED]
Sorry but what is delocalized bonding? And how will I be able to determine it when given the Lewis structure of a compound. Like what are its distinctions. I understand that its supposed to make it so that electrons are delocalized and spread across a compound, but I'm not really sure how I would se...
- Fri Dec 08, 2017 5:08 am
- Forum: Bronsted Acids & Bases
- Topic: Do we need to memorize table 12.2 and 12.3? [ENDORSED]
- Replies: 3
- Views: 635
Re: Do we need to memorize table 12.2 and 12.3? [ENDORSED]
I think the selected values will be given if needed in the question, I don't remember Lavelle saying anything about memorizing.
- Fri Dec 08, 2017 5:07 am
- Forum: Conjugate Acids & Bases
- Topic: 12.17
- Replies: 1
- Views: 309
Re: 12.17
Typically, non metal oxides are acidic. Metal oxides are basic. And semi metal oxides are amphoteric. If you can't determine it from that, then it's always a safe bet to draw the Lewis Structure and see if there are any lone pairs available (base), if it's an incomplete octet (acid). If it could go ...
- Fri Dec 08, 2017 4:58 am
- Forum: Lewis Acids & Bases
- Topic: 12.17
- Replies: 2
- Views: 401
Re: 12.17
Typically, non metal oxides are acidic. Metal oxides are basic. And semi metal oxides are amphoteric. If you can't determine it from that, then it's always a safe bet to draw the Lewis Structure and see if there are any lone pairs available (base), if it's an incomplete octet (acid). If it could go ...
- Thu Dec 07, 2017 11:53 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Equilibrium Shift
- Replies: 2
- Views: 224
Re: Equilibrium Shift
Liquids don't affect the equilibrium CONSTANT because their effective concentrations stay constant throughout the reaction. BUT, In terms of shifting the reaction itself, H20 is still viewed as a reactant. If you add more H20 concentration, that's not a constant value. When you add more reactants, t...
- Thu Dec 07, 2017 11:46 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Reaction shift
- Replies: 3
- Views: 244
Re: Reaction shift
The reaction will shift left to maintain equilibrium because of the excess amount of product. Concentration RATIOS must be maintained during and for equilibrium at all times.
- Fri Nov 17, 2017 9:10 am
- Forum: Hybridization
- Topic: axial vs equatorial lone pair
- Replies: 2
- Views: 1973
axial vs equatorial lone pair
Can someone explain the difference between axial lone pairs and equatorial lone pairs ?How can you tell what type of lone pair a given molecule has? And based on these pairs/shape, that's how we determine bond angles right?
Thank you!
Thank you!
- Thu Nov 09, 2017 12:38 am
- Forum: Ionic & Covalent Bonds
- Topic: 3.23
- Replies: 3
- Views: 534
Re: 3.23
Just realized you're trying to get to a noble gas configuration, nvm.
- Thu Nov 09, 2017 12:37 am
- Forum: Ionic & Covalent Bonds
- Topic: 3.23
- Replies: 3
- Views: 534
3.23
I understand the concept behind oxidation states (how much you can lose and gain to become an octet). But for the chlorine atom, how does an oxidation charge of (+7) which means it loses 7 electrons, get to a full octet when Chlorine already has 5 electrons, so losing 7 would get it to a full d orbi...
- Sun Oct 29, 2017 3:04 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbital Angular Momentum Quantum Number
- Replies: 2
- Views: 397
Re: Orbital Angular Momentum Quantum Number
^^, also don't forget that l also represents the rate of rotation.
- Sun Oct 29, 2017 3:02 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Exceptions to Electron Configuration [ENDORSED]
- Replies: 5
- Views: 2384
Re: Exceptions to Electron Configuration [ENDORSED]
I agree with Angelica! But in regards to the grouping, I remember Lavelle saying in class that groups in the periodic table are grouped together because of similiar properties, and so yes the groups did have more exceptions besides Chromium and Copper. But in regards to this particular test, and in ...
- Sun Oct 29, 2017 2:59 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: orbitals [ENDORSED]
- Replies: 5
- Views: 553
Re: orbitals [ENDORSED]
Basically, yes it is. There can only be two electrons in an orbital, and some subshells like d can contain more orbitals (so basically more electrons) than other subshells like p. D has five orbitals, or 10 electrons.
- Tue Oct 17, 2017 11:55 am
- Forum: Photoelectric Effect
- Topic: Post Module #29 (KJ*mol^-1 problem)
- Replies: 4
- Views: 551
Re: Post Module #29 (KJ*mol^-1 problem)
Yes, divide the Avogrado's constant in the dimensional analysis so you can convert the energy/sodium mole to energy/sodium atom
- Mon Oct 16, 2017 4:22 pm
- Forum: Photoelectric Effect
- Topic: Post Mod #28 pt b: conversion units [ENDORSED]
- Replies: 3
- Views: 329
Re: Post Mod #28 pt b: conversion units [ENDORSED]
The units for the work function will be given in either J or J/mol (or kJ or kJ/mol), but never kg/mol. When you are given the energy/mol, multiply by Avogrado's number to convert the work function in terms of energy/atom. I am so ashamed that I misread my own handwriting. It was in kj/mol this who...
- Mon Oct 16, 2017 1:07 pm
- Forum: Photoelectric Effect
- Topic: Post Mod #28 pt b: conversion units [ENDORSED]
- Replies: 3
- Views: 329
Post Mod #28 pt b: conversion units [ENDORSED]
The question asks for the energy required to remove an electron from the sodium atom. But the work function is given in units of kg*mol^-1. I know that a joule's SI base units is kg⋅m2⋅s−2. How would I convert that??
Thank you!
Thank you!
- Sun Oct 15, 2017 9:04 pm
- Forum: Properties of Light
- Topic: Question 1.15
- Replies: 2
- Views: 527
Re: Question 1.15
For the Rydberg equation, you're missing the frequency. So first, you need to find the frequency using the given wavelength. Find this using the c=wavelength*frequency formula. You can then use the calculated frequency for the Rydberg equation! (Remember that for these type of problems, if they don'...
- Sun Oct 15, 2017 8:52 pm
- Forum: Photoelectric Effect
- Topic: Work Function vs. Threshold Energy [ENDORSED]
- Replies: 5
- Views: 930
Re: Work Function vs. Threshold Energy [ENDORSED]
They're the same thing basically. Both represent the amount of energy needed to eject an electron. I think for test purposes though they use the term work function!