Search found 30 matches
- Mon Jun 04, 2018 9:22 pm
- Forum: Hybridization
- Topic: sp^3d or dsp^3
- Replies: 6
- Views: 822
Re: sp^3d or dsp^3
It should not matter which order you write it in, both ways say the same thing.
- Mon Jun 04, 2018 9:17 pm
- Forum: Lewis Structures
- Topic: Levels of electron density
- Replies: 1
- Views: 337
Re: Levels of electron density
Areas of electron density are simply grouping of electrons. So any bond counts as one area of electron density. A lone pair or even solo electron if the molecule is a radical would also count as a lone pair. The way I think about it is, when I draw a Lewis structure, any bond or grouping of free ele...
- Mon Jun 04, 2018 9:09 pm
- Forum: Lewis Structures
- Topic: Expanded octets
- Replies: 6
- Views: 661
Re: Expanded octets
Elements period 3 and below can expand their octets because they have a d-orbital and they can play with those electrons if necessary. They should be able to take an extra 10 electrons, the number of electrons in the d orbital.
- Mon May 28, 2018 2:35 pm
- Forum: Resonance Structures
- Topic: Radicals importance
- Replies: 3
- Views: 514
Re: Radicals importance
Radicals are common biproducts of bodily functions. Antioxidants react with radicals to stop them from damaging the body.
So basically, radicals are very reactive because their solo electron/s really want/s to find a partner.
So basically, radicals are very reactive because their solo electron/s really want/s to find a partner.
- Mon May 28, 2018 2:31 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Meaning
- Replies: 5
- Views: 989
Re: Formal Charge Meaning
I think they are related. Atoms with negative formal charges mean the electron density is higher around them. If the electron density is higher around them, then they should also have a negative dipole.
- Mon May 28, 2018 2:21 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: HW 4.13
- Replies: 2
- Views: 445
Re: HW 4.13
That actually makes perfect sense! Thank you so much!
- Fri May 25, 2018 5:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: HW 4.13
- Replies: 2
- Views: 445
HW 4.13
The problem asks for the molecular shape of I 3 - . The Lewis structure shows 3 lone pairs and 2 bonding pairs around the central Iodine. The solutions manual states the shape is linear. Why would the shape be linear if there is an odd number of lone pairs pushing on the atoms? I thought the molecul...
- Fri May 25, 2018 5:50 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizing power
- Replies: 10
- Views: 8755
Re: Polarizing power
Polarizing power refers to an atoms ability to pull an electron toward it, polarizing the atom the electron comes from. Since cations are positive, they are able to attract electrons toward themselves. Anions are negative and so do not attract more electrons.
- Fri May 25, 2018 5:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angle
- Replies: 6
- Views: 644
Re: Bond Angle
Linear: 180°
Trigonal planar: 120°
Tetrahedral: 109.5°
You can look at the shape of the molecule and estimate the bond angles based on these values. For example, if the bond angles look smaller than the bond angles of trigonal planar, then you would say "less than 120°".
Trigonal planar: 120°
Tetrahedral: 109.5°
You can look at the shape of the molecule and estimate the bond angles based on these values. For example, if the bond angles look smaller than the bond angles of trigonal planar, then you would say "less than 120°".
- Sat May 19, 2018 12:52 am
- Forum: Ionic & Covalent Bonds
- Topic: Melting and Boiling Points
- Replies: 3
- Views: 492
Re: Melting and Boiling Points
Covalent bonds, since they share electrons, absorb less energy than ionic bonds do before breaking. Melting and boiling point are both just a measure of how much heat, so how much energy, is required to move to the next state of matter. Thus, both the melting and boiling point of covalent bonds are ...
- Sat May 19, 2018 12:43 am
- Forum: Lewis Structures
- Topic: Naming compounds
- Replies: 3
- Views: 473
Re: Naming compounds
There is a fundamentals section breaking down chemical prefixes and suffixes that help break down and determine the meaning of chemical compound names.
- Sat May 19, 2018 12:36 am
- Forum: Dipole Moments
- Topic: Positive and Negative Dipole [ENDORSED]
- Replies: 2
- Views: 1607
Re: Positive and Negative Dipole [ENDORSED]
A negative dipole results from a side of the molecule being more negative than the others. So, the negative dipole should be on the atom that is more electronegative and can pull other electrons towards it to become more negative. Comparatively, the positive dipole goes with the lesser electronegati...
- Fri May 11, 2018 11:34 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: De Broglie Equation in Heisenberg Uncertainty Equation
- Replies: 2
- Views: 499
Re: De Broglie Equation in Heisenberg Uncertainty Equation
I think it's a good point to mention that both equations deal with all objects (instead of just photons) and with a wave model to support why this could work. If you were to replace substitute wavelength for velocity or vice versa, you would probably have to put Delta wavelength to match the variabl...
- Fri May 11, 2018 11:24 pm
- Forum: SI Units, Unit Conversions
- Topic: units
- Replies: 4
- Views: 664
Re: units
Also, velocity is used in equations as m/s so be careful to check that the info they give u is either in this form or you convert it to be.
- Fri May 11, 2018 11:17 pm
- Forum: Octet Exceptions
- Topic: expanded octet XeF4
- Replies: 8
- Views: 2199
Re: expanded octet XeF4
There explanation was that if you found the formal charges for the structure with and without double bonds, the one without would have charges closer to 0 and thus be the better structure for the molecule.
- Sun May 06, 2018 10:00 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Confusion about why there is no 1p, 1d, or 1f orbital? [ENDORSED]
- Replies: 4
- Views: 9052
Re: Confusion about why there is no 1p, 1d, or 1f orbital? [ENDORSED]
The letters correspond to the l value:
0 - s
1 - p
2 - d
3 - f
The l value equals all integers up to n-1. So in shell n=1, l=0. Thus, there is only 1s. For shell n=3, l=0,1,2. So 3s, 3p, and 3d exist.
0 - s
1 - p
2 - d
3 - f
The l value equals all integers up to n-1. So in shell n=1, l=0. Thus, there is only 1s. For shell n=3, l=0,1,2. So 3s, 3p, and 3d exist.
- Sun May 06, 2018 9:53 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Exceptions for Electron Configuartions
- Replies: 5
- Views: 938
Re: Exceptions for Electron Configuartions
Okay so 4s fills before 3d because before the 3d subshell has any electrons shoved into it, 4s actually has a lower energy level than 3d. This is actually pretty cool because it allows us to simply read across the period when writing the electron configuration. For example, you stated the noble gas ...
- Sun May 06, 2018 9:31 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: What Exactly IS an Orbital?
- Replies: 2
- Views: 477
Re: What Exactly IS an Orbital?
It helps to know where the word comes from. An orbit is a constant path something takes. Scientists knew that they couldn't map the exact orbit of an electron, so they named the path an orbital to give the sense that the electron moves in a pattern but to emphasize that they couldn't be sure how. So...
- Thu Apr 26, 2018 9:14 pm
- Forum: Properties of Electrons
- Topic: Information Provided on Exam
- Replies: 6
- Views: 760
Re: Information Provided on Exam
Not 100% sure, but you may be given the the frequencies of blue and red light.
MORE IMPORTANTLY, if you know that the wavelength for red light is 700 nm and for violet light is 400 nm, you're set.
MORE IMPORTANTLY, if you know that the wavelength for red light is 700 nm and for violet light is 400 nm, you're set.
- Thu Apr 26, 2018 9:10 pm
- Forum: DeBroglie Equation
- Topic: DeBroglie
- Replies: 7
- Views: 782
Re: DeBroglie
Light does have a momentum. The photons however do not have a mass. So I suppose if the problem gave you a value for the momentum (p), you could use the de Broglie wavelength as normal. Otherwise, this equation doesn't work for light.
- Thu Apr 26, 2018 9:03 pm
- Forum: Properties of Electrons
- Topic: electron mass
- Replies: 15
- Views: 1669
Re: electron mass
The test definitely gives you the mass of an electron.
- Sun Apr 22, 2018 6:21 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Formula
- Replies: 4
- Views: 434
Re: Rydberg Formula
In class, Lavelle said he didn't like the Rydberg equation because it wasn't obvious how to derive it. Should we still know it, or should we just stick with the En=-hR/n^2 equation he did the example with?
- Sun Apr 22, 2018 6:14 pm
- Forum: Photoelectric Effect
- Topic: Plastic vs Metal [ENDORSED]
- Replies: 3
- Views: 497
Re: Plastic vs Metal [ENDORSED]
What about a conductive substance that is not a metal? For example, salt water can conduct electricity, but is not a solid metal. Could the experiment still be conducted and produce an ejected electron?
- Sun Apr 22, 2018 6:08 pm
- Forum: Significant Figures
- Topic: Use of sigfigs
- Replies: 8
- Views: 933
Re: Use of sigfigs
Remember to only take the sigfig at the end for better accuracy. Keep the full values until you have solved the problem, and then take the sigfig of that final value.
- Sat Apr 14, 2018 7:53 pm
- Forum: Significant Figures
- Topic: Sig Figs Multiplication [ENDORSED]
- Replies: 3
- Views: 529
Re: Sig Figs Multiplication [ENDORSED]
Addition and subtraction are actually a lot simpler. You just need to look at your original data and see which one has the least amount of decimal places. That number is how many decimal places your answer should have. Example: 4262.3 + 45.61 42.67 has the least amount of sigfigs, but for addition a...
- Sat Apr 14, 2018 7:45 pm
- Forum: Significant Figures
- Topic: Sig Figs Multiplication [ENDORSED]
- Replies: 3
- Views: 529
Re: Sig Figs Multiplication [ENDORSED]
For multiplication and division, you are going to use the smallest number of sigfigs in your original data.
Example: 3.23 x 2.4
2.4 has the least amount of sigfigs, 2. So the answer should be written with two sigfigs.
7.752 -> 7.8
Example: 3.23 x 2.4
2.4 has the least amount of sigfigs, 2. So the answer should be written with two sigfigs.
7.752 -> 7.8
- Sat Apr 14, 2018 7:36 pm
- Forum: *Black Body Radiation
- Topic: Black Body? [ENDORSED]
- Replies: 13
- Views: 2147
Re: Black Body? [ENDORSED]
So as the second post under this topic explains, black bodies absorb all light in the electromagnetic spectrum and emit thermal radiation. However, when they get too hot, they emit light. The sun follows this definition. The sun is very hot, so it emits light. As large stars cool down and die, they ...
- Sun Apr 08, 2018 9:44 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3619387
Re: Post All Chemistry Jokes Here
I try to tell chemistry jokes, but there's no reaction :'(
- Sun Apr 08, 2018 9:38 pm
- Forum: Ionic & Covalent Bonds
- Topic: Types of Bonds
- Replies: 10
- Views: 1261
Re: Types of Bonds
Can I apply a similar logic to ionic and metallic bonds? If so, what is it?
- Sun Apr 08, 2018 9:32 pm
- Forum: Ionic & Covalent Bonds
- Topic: Types of Bonds
- Replies: 10
- Views: 1261
Types of Bonds
How would you look at a compound and quickly determine it to be a covalent bond? Without actually working out electron sharing.