Search found 37 matches

by Moura Girgis 1D
Tue Nov 24, 2020 7:20 pm
Forum: General Science Questions
Topic: # of chem posts
Replies: 20
Views: 161

Re: # of chem posts

Alison Perkins 2C wrote:
jasmineculilap_2J wrote:You need 5 posts per week, so 35 posts are needed.

Do general questions and jokes count? Or strictly chemistry material?


Pretty sure that everything/anything posted counts!
by Moura Girgis 1D
Mon Nov 23, 2020 11:45 pm
Forum: *Shrodinger Equation
Topic: SE importance
Replies: 4
Views: 24

Re: SE importance

This equation basically refers to electron density and the likelihood of finding an electron within it.
by Moura Girgis 1D
Mon Nov 23, 2020 11:42 pm
Forum: Empirical & Molecular Formulas
Topic: Finding Mass % Composition
Replies: 4
Views: 58

Re: Finding Mass % Composition

SamayaJoshi1A wrote:Hi! I don't think this is a necessary step for any of the questions. Dr. Lavelle just does this to show that there is a ratio and that the percentages should add up to 100 percent.


I agree, Dr. Lavelle just tries to show us the w=actual process, but it is not necessary.
by Moura Girgis 1D
Mon Nov 23, 2020 11:40 pm
Forum: Balancing Chemical Reactions
Topic: States of matter in chem equations
Replies: 12
Views: 68

Re: States of matter in chem equations

Although they should not have much of an effect on your answer, I would put it just in case :)
by Moura Girgis 1D
Mon Nov 23, 2020 11:39 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8245
Views: 1438638

Re: Post All Chemistry Jokes Here

Q: What is the chemical formula for "coffee"?
A: CoFe2
Q: What is the chemical formula for "banana"?
A: BaNa2
by Moura Girgis 1D
Mon Nov 23, 2020 11:38 pm
Forum: Administrative Questions and Class Announcements
Topic: How to find my posts
Replies: 78
Views: 49084

Re: How to find my posts

All you have to do is go to "Quick Links" and then "Your Posts" !
by Moura Girgis 1D
Mon Nov 23, 2020 11:36 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass and Molecular Mass Difference?
Replies: 19
Views: 177

Re: Molar Mass and Molecular Mass Difference?

Those two are pretty interchangeable, they just require different units I think.
by Moura Girgis 1D
Sun Nov 15, 2020 11:54 am
Forum: Trends in The Periodic Table
Topic: Atomic radius
Replies: 4
Views: 26

Re: Atomic radius

Hi! I agree with the post above, and if I recall correctly, the horizontal trend is a bit stronger than the vertical. However, I'm unsure if there are any straight up exceptions to the atomic radius trend. I think Dr. Lavelle might have mentioned these exceptions in his pervious lectures where he d...
by Moura Girgis 1D
Sun Nov 15, 2020 11:49 am
Forum: Student Social/Study Group
Topic: Online textbook answer key
Replies: 5
Views: 124

Re: Online textbook answer key

Maybe you could try downloading the the answer key and then opening it from there? That's what I did so now the answer key is saved on my computer and I can access it anytime I want.
by Moura Girgis 1D
Sun Nov 15, 2020 11:46 am
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 189
Views: 34573

Re: Final Jitters

I always eat a good, healthy, meal the day before my test and something light light a nutrition bar the morning of. That usually keeps me energized helps me think better when taking the test.
by Moura Girgis 1D
Sun Nov 15, 2020 11:44 am
Forum: Administrative Questions and Class Announcements
Topic: How to list Chem_Mod posts
Replies: 18
Views: 40126

Re: How to list Chem_Mod posts

This is so helpful, thank you!! Also, I think Chem_mod might be Dr. Lavelle only, not too sure though.
by Moura Girgis 1D
Sun Nov 15, 2020 11:40 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8245
Views: 1438638

Re: Post All Chemistry Jokes Here

I see that everyone is making bad chemistry jokes because all the good ones Argon.

Q: What did the scientist say when he found 2 isotopes of helium?
A: HeHe
by Moura Girgis 1D
Sun Nov 08, 2020 4:18 pm
Forum: Trends in The Periodic Table
Topic: # of electrons
Replies: 23
Views: 87

Re: # of electrons

We can count the number of elements within an atom based on its atomic number, which is also the number of protons in that element. In an ion, it would be the atomic number plus the charge (negative or positive).
by Moura Girgis 1D
Sun Nov 08, 2020 4:14 pm
Forum: Electronegativity
Topic: Electronegativity trend
Replies: 18
Views: 81

Re: Electronegativity trend

Electronegativity trend is ultimately very similar to the ionization energy trend, as it increases in the periodic table from left to right and decreases down the periodic table.
by Moura Girgis 1D
Sun Nov 08, 2020 4:08 pm
Forum: Lewis Structures
Topic: Lone Pairs Question
Replies: 22
Views: 92

Re: Lone Pairs Question

In regards to a Lewis structure, a long pair consists of valence electrons of one atoms which are neither bonded nor shared with any other atom.
by Moura Girgis 1D
Sun Nov 08, 2020 4:06 pm
Forum: Ionic & Covalent Bonds
Topic: Extra Valence Electrons
Replies: 10
Views: 46

Re: Extra Valence Electrons

As Dr. Lavelle had mentioned in one of his previous lectures, these elements would be exceptions to the octet rule, which is why they could hold that extra electron.
by Moura Girgis 1D
Sun Nov 08, 2020 4:04 pm
Forum: Administrative Questions and Class Announcements
Topic: How to find my posts
Replies: 78
Views: 49084

Re: How to find my posts

All you have to do is click on "Quick links" on the top left, then go to "your posts." You can filter it so that you check what posts you made within a select time frame.
by Moura Girgis 1D
Fri Oct 30, 2020 5:59 pm
Forum: Properties of Electrons
Topic: What does this symbol mean?
Replies: 11
Views: 92

Re: What does this symbol mean?

That symbol stands for "proportional to" and is used to describe how one thing is the same as or equal to another thing. Similarly, it can be used to describe something as "inversely proportional" to another thing when that second term has a "^-1" on it.
by Moura Girgis 1D
Fri Oct 30, 2020 5:53 pm
Forum: Properties of Light
Topic: Wavelength
Replies: 14
Views: 77

Re: Wavelength

When solving a problem, wavelength must always be written in terms of m, since the other variables in the equation would be in m. However, when writing the wavelength as the final answer, it should be converted to nm in order to determine the spectrum.
by Moura Girgis 1D
Fri Oct 30, 2020 5:49 pm
Forum: Properties of Light
Topic: rydberg's constant
Replies: 10
Views: 69

Re: rydberg's constant

The the several practice problems we have done for this class so far, the value for the Rydberg constant was 3.289x10^15, so that should be the only value you use when solving the problems as far as Chem14A goes.
by Moura Girgis 1D
Fri Oct 30, 2020 5:45 pm
Forum: Properties of Light
Topic: Is c always the speed of light?
Replies: 72
Views: 245

Re: Is c always the speed of light?

Yes! At least so far in Chem14A c is always a constant which represents the speed of light, so it should not change.
by Moura Girgis 1D
Fri Oct 30, 2020 5:42 pm
Forum: Properties of Light
Topic: Midterm
Replies: 42
Views: 369

Re: Midterm

The midterm was about 12 problems, with 50 minutes given for us to complete it. We could use the constants and equations handout as well as the periodic table handout as long as we printed it out and did not write anything on it.
by Moura Girgis 1D
Thu Oct 22, 2020 10:23 pm
Forum: Properties of Light
Topic: Electrons Emitted
Replies: 7
Views: 41

Re: Electrons Emitted

Since kinetic energy would be 0 in this scenario, you would just have to divide the total energy by the work function, taking into account whatever is already given to you or whatever you have previously solved in the problem.
by Moura Girgis 1D
Thu Oct 22, 2020 10:17 pm
Forum: Properties of Light
Topic: Units for wavelength/frequency
Replies: 18
Views: 84

Re: Units for wavelength/frequency

The units for wavelength is in meters, and the units for frequency is in Hz, or s^-1. Since the midterm is multiple choice, the only thing you should worry about in terms of units is being able to convert if it is given in any other unit, such as nanometers instead of meters.
by Moura Girgis 1D
Thu Oct 22, 2020 10:14 pm
Forum: Molarity, Solutions, Dilutions
Topic: What does mmol stand for?
Replies: 30
Views: 246

Re: What does mmol stand for?

Just like in mg, the m stand for milligrams, the m in mol stands for milligrams. It is simply the prefix "milli."
by Moura Girgis 1D
Thu Oct 22, 2020 10:09 pm
Forum: Balancing Chemical Reactions
Topic: Writing Equations
Replies: 8
Views: 72

Re: Writing Equations

So when asking us to write an equation with an element that happens to be diatomic, like oxygen, would we always but a subscript of 2 with it? Because I feel like I have seen instances where there wasn't any subscripts with it.
by Moura Girgis 1D
Wed Oct 21, 2020 9:41 pm
Forum: Photoelectric Effect
Topic: How to calculate the kinetic energy, energy and frequency? [ENDORSED]
Replies: 20
Views: 4436

Re: How to calculate the kinetic energy, energy and frequency? [ENDORSED]

AustinMcBrideDisc3C wrote:
diegomartinez1F wrote:Mass of electron is given:

Me= 9.10938 x 10^-31 kg


Do we need to convert this to grams or can we keep it as kg?


We need to keep it in kg, as all of the other units include kg, such as Joules (kg.m^2/s^2)
by Moura Girgis 1D
Thu Oct 15, 2020 2:38 am
Forum: Balancing Chemical Reactions
Topic: Whole Number Stoichiometric Coefficients
Replies: 12
Views: 71

Re: Whole Number Stoichiometric Coefficients

It is much easier to work with whole number in balanced stoichiometric equations, so that is recommended, although fractions in a balanced equation would not technically be wrong, just harder to work out. Dr. Lavelle also mentioned it would be better to use whole numbers when balancing stoichiometri...
by Moura Girgis 1D
Thu Oct 15, 2020 2:35 am
Forum: Balancing Chemical Reactions
Topic: Balancing equations.
Replies: 35
Views: 657

Re: Balancing equations.

When balancing chemical equations, I found that what helps me best so that I am not confused between the different, changing, numbers for each element, is to list all elements on both the reactant side and product side, and when the numbers change in each element, it is best to cross out the previou...
by Moura Girgis 1D
Thu Oct 15, 2020 2:30 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Mass and Molecular Mass Difference?
Replies: 19
Views: 177

Re: Molar Mass and Molecular Mass Difference?

How would you know which units to use per molar mass and which to use for molecular mass? Is it grams and moles for molar mass but formula units for molecular mass?
by Moura Girgis 1D
Thu Oct 15, 2020 2:28 am
Forum: Molarity, Solutions, Dilutions
Topic: Homework problem Fundamentals E.15
Replies: 3
Views: 449

Re: Homework problem Fundamentals E.15

In order to solve this problem, you must first find the given molar mass of the metal, which is 74.10 grams per mole, then figure out that the mass of the hydroxide (OH) is 34.02 grams per mole. Then subtract the 74.10 from the 34.02 you calculated, and you'd get 40.08 grams per mole, which would be...
by Moura Girgis 1D
Thu Oct 15, 2020 2:18 am
Forum: Balancing Chemical Reactions
Topic: Naming compounds
Replies: 21
Views: 150

Re: Naming compounds

I'm pretty sure that compounds would be provided, as I think we start learning how to name compounds in organic chemistry. It could still be useful information to know, though.
by Moura Girgis 1D
Thu Oct 08, 2020 4:15 pm
Forum: Balancing Chemical Reactions
Topic: Combustion
Replies: 14
Views: 173

Re: Combustion

I think that, in addition to all the previous comments, Dr. Lavelle could have been referring to the fact that in all these reactions, the products tend to be in a gaseous state.
by Moura Girgis 1D
Thu Oct 08, 2020 4:07 pm
Forum: Molarity, Solutions, Dilutions
Topic: Sapling Week 1 HW_problem #9
Replies: 9
Views: 107

Re: Sapling Week 1 HW_problem #9

I also had a tough time trying to work this problem out, as I had to do a lot of different conversions between elements in order to find my answer. These replies really helped me out and gave be a solid foundation as to how I had to start this problem and what I had to do in order to get the answer,...
by Moura Girgis 1D
Thu Oct 08, 2020 4:03 pm
Forum: Balancing Chemical Reactions
Topic: State in chemical reactions
Replies: 13
Views: 112

Re: State in chemical reactions

Will we be penalized for not including the state of each element in the chemical reactions? It's easier for me to visualize the formula without the extra information but I don't know if that's something that's important to have in the answer. To add on to this question, does anyone have any tips fo...
by Moura Girgis 1D
Tue Oct 06, 2020 8:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 71
Views: 4417

Re: Step Up Sessions

t_rasul3I wrote:Can I just join any UA peer learning session?

yes, from my understanding all UA peer learning sessions can be accessed by any student, regardless of your lecture or discussion.
by Moura Girgis 1D
Mon Oct 05, 2020 7:22 pm
Forum: SI Units, Unit Conversions
Topic: SI Units in Answer?
Replies: 15
Views: 149

Re: SI Units in Answer?

As you are working through the problem, it is best to use whatever units are given in the question. Or, if the question is giving you a problem in a specific unit measurement, but is asking for a different one, you must convert to the units asked either before you begin solving or once you got the a...

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