Search found 47 matches
- Sun Jun 10, 2018 10:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape of AX5E
- Replies: 5
- Views: 2343
Re: Shape of AX5E
I believe that this would be a square pyramidal
- Sun Jun 10, 2018 10:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: sigma and pi bond
- Replies: 2
- Views: 431
sigma and pi bond
I am quite confused on how to determine a sigma bond from a pi bond can anyone help?
- Sun Jun 10, 2018 10:37 pm
- Forum: Hybridization
- Topic: basics of hybridization
- Replies: 18
- Views: 2487
Re: basics of hybridization
One thing I found helpful for hybridization is basically if its 1-attachment= S , 2-attachment= SP , 3-attachment=sp^(2), 4-attachment= sp^(3), 5-attachment= SP^(3)D, 6--attachment = SP^(3)D^(2).
- Sun Jun 03, 2018 4:02 pm
- Forum: Octet Exceptions
- Topic: expanded octet
- Replies: 12
- Views: 2708
expanded octet
How would we know when an atom has an expanded octet do we just have to know what are the exceptions by memory? if so what are they?
- Sun Jun 03, 2018 3:59 pm
- Forum: Lewis Structures
- Topic: Electrons in Valence Shell
- Replies: 4
- Views: 834
Re: Electrons in Valence Shell
I believe it depends on what you are looking at because some atoms can have expanded octets while others can not.
- Sun Jun 03, 2018 3:58 pm
- Forum: Lewis Structures
- Topic: d-block Lewis structures
- Replies: 3
- Views: 540
Re: d-block Lewis structures
The process would be the same as a normal lewis structure count the electrons and draw accordingly.
- Sun May 27, 2018 11:43 am
- Forum: Electronegativity
- Topic: Calculating electronegativity
- Replies: 10
- Views: 1330
Re: Calculating electronegativity
I don't believe we have to have it memorized we just need to know the pattern so it increases across and decreases down a column.
- Sun May 27, 2018 11:40 am
- Forum: Dipole Moments
- Topic: Polarization
- Replies: 2
- Views: 431
Re: Polarization
To determine the polarity of an atom the difference in electronegativity is an important component for example the more the difference in electronegativity the more polar it is. but they can be covalent as well.
- Sun May 27, 2018 11:36 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Difference in bonds
- Replies: 3
- Views: 580
Difference in bonds
I am confused on how to tell which bond is stronger for example when comparing a single bond with a triple bond how do we know which is shorter or longer? also how do we know whether one is stronger or weaker?
- Sun May 20, 2018 3:59 pm
- Forum: Ionic & Covalent Bonds
- Topic: double and triple bonds?
- Replies: 2
- Views: 302
double and triple bonds?
how would we know when to use a double bond or even a triple bond is there some sort of pattern? or should we just know?
- Sun May 20, 2018 3:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: Formal charge?
- Replies: 12
- Views: 1440
Formal charge?
What is formal charge and how do we calculate it?
- Sun May 20, 2018 3:54 pm
- Forum: Ionic & Covalent Bonds
- Topic: Octet rule
- Replies: 17
- Views: 2417
Re: Octet rule
The octet rule is when main group elements combine in a certain way so that each atom has eight electrons in its valence shell.
- Sun May 20, 2018 3:51 pm
- Forum: Ionic & Covalent Bonds
- Topic: Configurations
- Replies: 4
- Views: 558
Re: Configurations
You remove from the outermost electrons as they are the furthest away from the nucleus and require less energy to remove.
- Sun May 13, 2018 11:36 am
- Forum: Lewis Structures
- Topic: formal charge?
- Replies: 3
- Views: 2454
formal charge?
I understand how to draw a lewis structure but how would I come to do this if there are two elements such as CCL4 and what is meant by the formal charge? this might be simpler than I am making it out to be but I'm quite confused.
- Sun May 13, 2018 11:34 am
- Forum: Lewis Structures
- Topic: SO2
- Replies: 5
- Views: 829
Re: SO2
it would be more stable with two double bonds
- Sun May 13, 2018 11:33 am
- Forum: Lewis Structures
- Topic: Order of Dots
- Replies: 11
- Views: 1266
Re: Order of Dots
I believe they have to be balanced but it all corresponds to the number of electrons that element has
- Sun May 06, 2018 5:24 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: electron configuration of chromium? [ENDORSED]
- Replies: 3
- Views: 634
electron configuration of chromium? [ENDORSED]
I worked on a problem to find out the ground state electron configuration for chromium and was told it is [Ar] 3d^3 4s^1 why isn't it 3d^4 if it is in the fourth box of the d-block?
- Sun May 06, 2018 5:21 pm
- Forum: Trends in The Periodic Table
- Topic: electronegativity
- Replies: 4
- Views: 571
electronegativity
I am highly confused as to how to know when an element has a higher electronegativity than another element for example why does oxygen have a higher electronegativity than nitrogen? can someone explain this to me thoroughly?
- Sun May 06, 2018 5:14 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: half full?
- Replies: 5
- Views: 614
half full?
What is meant by the phrase it is half full in the context of orbitals? for example how do we know when an orbital is half full or completely full?
- Sun May 06, 2018 5:12 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 3d orbital
- Replies: 3
- Views: 485
Re: 3d orbital
A d orbital is an exception as spoken by Professor Lavelle as it depends on the concept that it is at a much higher energy level.
- Sun May 06, 2018 5:06 pm
- Forum: DeBroglie Equation
- Topic: Calculating wavelength of an electron
- Replies: 4
- Views: 614
Re: Calculating wavelength of an electron
In order to calculate the wavelength you will use the equation λ=h/mv
- Sun May 06, 2018 4:59 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Shapes of orbitals
- Replies: 6
- Views: 778
Re: Shapes of orbitals
No we will not be required to know how to draw the orbitals however, I do believe we have to how to distinguish between them
- Mon Apr 30, 2018 4:06 pm
- Forum: DeBroglie Equation
- Topic: De Brogiles wavelength
- Replies: 4
- Views: 735
De Brogiles wavelength
What is the wavelength of a neon atom traveling with a velocity of 4.34 X 10^3 m/s? There was a similar question to this on test 2 but I wasn't sure how to do the problem would I convert the moles to atoms then convert grams to kilograms and once I got that it will give me the mass and finally use λ...
- Mon Apr 30, 2018 4:02 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectra
- Replies: 1
- Views: 300
Atomic Spectra
In a hydrogen atom, an electron transitions from the fourth to the third quantum level. calculate the frequency of a photon emitted. These problems seem to confuse me I know the problem indicates the n=4 to n=3 which means it decreased however I'm not to sure if I did it correct I used the equation ...
- Mon Apr 30, 2018 3:52 pm
- Forum: Photoelectric Effect
- Topic: light problem
- Replies: 2
- Views: 596
light problem
A compound emits light with energy of 4.60 X 10^-19 J per photon. What is the wavelength of the light wave emitted by the compound in nanometers? I know that for this problem I would have to use the formula E=hc/λ and plugged in the constants and rearranged the equation in which now I got λ= h/E and...
- Mon Apr 30, 2018 3:42 pm
- Forum: Photoelectric Effect
- Topic: Test 2 final question [ENDORSED]
- Replies: 15
- Views: 1891
Re: Test 2 final question [ENDORSED]
it is a one to one ratio so it would be one thousand aswell.
- Mon Apr 30, 2018 3:40 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect
- Replies: 12
- Views: 1132
Re: Photoelectric Effect
The energy of the photon has to be either equal or greater than the energy of the electron for it to be emitted.
- Mon Apr 30, 2018 3:36 pm
- Forum: Photoelectric Effect
- Topic: What is work function? [ENDORSED]
- Replies: 15
- Views: 5721
Re: What is work function? [ENDORSED]
A work function is the minimum energy needed to remove an electron from a solid surface to a point in the vacuum immediately outside the solid surface.
- Sun Apr 22, 2018 1:19 pm
- Forum: Properties of Light
- Topic: 1.25 [ENDORSED]
- Replies: 1
- Views: 564
1.25 [ENDORSED]
Sodium vapor lamps used for public lighting, emit yellow light of wavelength 589 nm. how much energy is emitted by (a) an excited sodium atom when it generates a photon?
how would I approach this problem and what equation would I use?
how would I approach this problem and what equation would I use?
- Sun Apr 22, 2018 1:15 pm
- Forum: Einstein Equation
- Topic: constants [ENDORSED]
- Replies: 2
- Views: 407
constants [ENDORSED]
Are we supposed to memorize all the constants such as speed of light planks constant etc. and the equations as well? I think we are giving the constants but not the equations but I'm not to sure; any clarification?
- Sun Apr 22, 2018 1:11 pm
- Forum: Properties of Light
- Topic: frequency and wavelength [ENDORSED]
- Replies: 5
- Views: 1505
frequency and wavelength [ENDORSED]
What is the relationship between frequency and wavelength how does one affect the other?
- Sun Apr 22, 2018 12:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test Number 1
- Replies: 10
- Views: 1249
Re: Test Number 1
The average I believe was around 22/40 as well as in my discussion section the average was 21 because many students did not get to finish the test so, the average was not very high.
- Sun Apr 22, 2018 12:48 pm
- Forum: Properties of Light
- Topic: Speed of Light which is more accurate? [ENDORSED]
- Replies: 6
- Views: 2250
Re: Speed of Light which is more accurate? [ENDORSED]
For the speed of light I recommend using the most accurate, but rounding up to 3.00 will be fine as well as long as we use either one we are going to get an appropriate answer.
- Sun Apr 22, 2018 12:40 pm
- Forum: Properties of Light
- Topic: Test 2 [ENDORSED]
- Replies: 4
- Views: 597
Re: Test 2 [ENDORSED]
for the test we are going to be given the constant but I do believe that we might need to know the formulas that we are to use.
- Sun Apr 15, 2018 9:14 pm
- Forum: Properties of Light
- Topic: Equations [ENDORSED]
- Replies: 8
- Views: 726
Re: Equations [ENDORSED]
In order to know what equation to use you would have to look at the problem and distinguish what will be needed and in some instances as seen on Friday lecture we will need to rearrange the equations in order to obtain the answer. Always check what is given in order to get to the answer.
- Sat Apr 14, 2018 9:04 pm
- Forum: Properties of Light
- Topic: formula for light problems
- Replies: 2
- Views: 389
formula for light problems
I noticed that Dr. Lavelle rearranged the formula of E=hv and c= λv in Fridays lecture to solve the problem given in class and he got E=hc/λ, do we always have to do this in order to solve the problem? how do we know we have to rearrange the equations?
- Sat Apr 14, 2018 8:28 pm
- Forum: Properties of Light
- Topic: help on the question from Fridays lecture [ENDORSED]
- Replies: 2
- Views: 265
help on the question from Fridays lecture [ENDORSED]
If 3.61 X 10^-14 j is required to remove an electron with zero kinetic energy from a metal surface, what would be the longest wavelength light that could do this? I am aware we are to rearrange the equation and get hc/E but I'm not to sure what he did after that I don't understand how he got the fin...
- Sat Apr 14, 2018 8:22 pm
- Forum: Properties of Light
- Topic: wavelength description [ENDORSED]
- Replies: 11
- Views: 1247
wavelength description [ENDORSED]
In Mondays lecture Dr. Lavelle demonstrated the figure of the electric field and described what a wavelength was considered however, I am still confused as to what does amplitude mean in this context is it the height of the wavelength or...?
- Sat Apr 14, 2018 8:17 pm
- Forum: Limiting Reactant Calculations
- Topic: Two limiting reactants?
- Replies: 10
- Views: 2493
Re: Two limiting reactants?
No there could not be two limiting reactants as there has to be one which will run out and another in which we will have an excess of there can not be two limiting.
- Sat Apr 14, 2018 8:12 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical and Molecular Formulas [ENDORSED]
- Replies: 4
- Views: 424
Re: Empirical and Molecular Formulas [ENDORSED]
Yes as I remember we were given the figure of the atoms themselves and in order to fine the formula we were to count each of the elements given and that would give us the molecular formula.
- Sat Apr 14, 2018 8:09 pm
- Forum: Significant Figures
- Topic: Sig fifs in 750 [ENDORSED]
- Replies: 6
- Views: 1378
Re: Sig fifs in 750 [ENDORSED]
yes the value of 750 only has 2 significant figures as a significant figure is any non-zero digit and because it came after too the right of the 75 it is not considered a significant figure which is why it only contains 2.
- Sat Apr 07, 2018 5:54 pm
- Forum: Balancing Chemical Reactions
- Topic: How to know the state of the molecules [ENDORSED]
- Replies: 6
- Views: 840
Re: How to know the state of the molecules [ENDORSED]
I am quite certain that we as students are not required to know the states of the molecules as most of the time they are given in the problem.
- Sat Apr 07, 2018 5:22 pm
- Forum: SI Units, Unit Conversions
- Topic: why do I not use avogadro's number
- Replies: 5
- Views: 1943
why do I not use avogadro's number
I am confused in a problem that involves conversions to atoms. For example, Mass of an atom of beryllium is 1.50 X 10^(-26)kg. How many beryllium atoms are present in a beryllium film of mass 0.210 g. I know the answer is 1.50 X 10^(-26)kg. * (1000 grams) =1.5 X10^(-23) and now I will have to divide...
- Sat Apr 07, 2018 5:07 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing equations with fractions [ENDORSED]
- Replies: 13
- Views: 1636
Balancing equations with fractions [ENDORSED]
Balancing equations can be quite confusing when fractions get involved for me. For example for the chemical equation NH3+O2--------->NO+H2O I balanced it and obtained the answer 2NH3+(5/2) O(2)-------->2NO+3H2O, could I leave the fraction or would I have to multiply the whole equation by two in orde...
- Sat Apr 07, 2018 4:56 pm
- Forum: Limiting Reactant Calculations
- Topic: Limiting reagent of NH(3) +CuO------->N(2)+H2O+CO
- Replies: 3
- Views: 1060
Limiting reagent of NH(3) +CuO------->N(2)+H2O+CO
I understand that In this problem I am to balance the chemical equation, NH(3) +CuO------->N(2)+H2O+CO, which becomes 2NH(3)+3CuO--------->N2 +3H2O+3Cu, after that I have to find the moles of NH3(2.9 mol) and CuO (1.13 mol) however, from here I know I am to find the moles needed for each but, I am n...
- Thu Oct 05, 2017 5:40 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical Coefficients [ENDORSED]
- Replies: 12
- Views: 5796
Re: Empirical Coefficients [ENDORSED]
When the answer you acquire is close to a whole number such as 2.9 it is better to round up to 3 and not having to multiple by another number as it already is a whole number.
- Thu Oct 05, 2017 5:33 pm
- Forum: SI Units, Unit Conversions
- Topic: Molar Mass
- Replies: 7
- Views: 1602
Re: Molar Mass
What kind of helps me remember the difference between molar mass and molecular weight is the molar mass is what the entire compound equals for example H20 would have a molar mass of 17.01 while the weight of lets say hydrogen would only be 1.01.