Search found 30 matches

by Shimran Kumar 1C
Mon Jun 04, 2018 9:22 pm
Forum: Hybridization
Topic: sp^3d or dsp^3
Replies: 6
Views: 262

Re: sp^3d or dsp^3

It should not matter which order you write it in, both ways say the same thing.
by Shimran Kumar 1C
Mon Jun 04, 2018 9:17 pm
Forum: Lewis Structures
Topic: Levels of electron density
Replies: 1
Views: 131

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...
by Shimran Kumar 1C
Mon Jun 04, 2018 9:09 pm
Forum: Lewis Structures
Topic: Expanded octets
Replies: 6
Views: 225

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.
by Shimran Kumar 1C
Mon May 28, 2018 2:35 pm
Forum: Resonance Structures
Topic: Radicals importance
Replies: 3
Views: 218

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.
by Shimran Kumar 1C
Mon May 28, 2018 2:31 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Meaning
Replies: 5
Views: 296

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.
by Shimran Kumar 1C
Mon May 28, 2018 2:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW 4.13
Replies: 2
Views: 121

Re: HW 4.13

That actually makes perfect sense! Thank you so much!
by Shimran Kumar 1C
Fri May 25, 2018 5:55 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW 4.13
Replies: 2
Views: 121

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...
by Shimran Kumar 1C
Fri May 25, 2018 5:50 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing power
Replies: 10
Views: 546

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.
by Shimran Kumar 1C
Fri May 25, 2018 5:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 6
Views: 211

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°".
by Shimran Kumar 1C
Sat May 19, 2018 12:52 am
Forum: Ionic & Covalent Bonds
Topic: Melting and Boiling Points
Replies: 3
Views: 116

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 ...
by Shimran Kumar 1C
Sat May 19, 2018 12:43 am
Forum: Lewis Structures
Topic: Naming compounds
Replies: 3
Views: 167

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.
by Shimran Kumar 1C
Sat May 19, 2018 12:36 am
Forum: Dipole Moments
Topic: Positive and Negative Dipole [ENDORSED]
Replies: 2
Views: 116

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...
by Shimran Kumar 1C
Fri May 11, 2018 11:34 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: De Broglie Equation in Heisenberg Uncertainty Equation
Replies: 2
Views: 219

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...
by Shimran Kumar 1C
Fri May 11, 2018 11:24 pm
Forum: SI Units, Unit Conversions
Topic: units
Replies: 4
Views: 285

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.
by Shimran Kumar 1C
Fri May 11, 2018 11:17 pm
Forum: Octet Exceptions
Topic: expanded octet XeF4
Replies: 8
Views: 354

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.
by Shimran Kumar 1C
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: 507

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.
by Shimran Kumar 1C
Sun May 06, 2018 9:53 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions for Electron Configuartions
Replies: 5
Views: 214

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 ...
by Shimran Kumar 1C
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: 115

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...
by Shimran Kumar 1C
Thu Apr 26, 2018 9:14 pm
Forum: Properties of Electrons
Topic: Information Provided on Exam
Replies: 6
Views: 298

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.
by Shimran Kumar 1C
Thu Apr 26, 2018 9:10 pm
Forum: DeBroglie Equation
Topic: DeBroglie
Replies: 7
Views: 261

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.
by Shimran Kumar 1C
Thu Apr 26, 2018 9:03 pm
Forum: Properties of Electrons
Topic: electron mass
Replies: 15
Views: 568

Re: electron mass

The test definitely gives you the mass of an electron.
by Shimran Kumar 1C
Sun Apr 22, 2018 6:21 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Formula
Replies: 4
Views: 151

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?
by Shimran Kumar 1C
Sun Apr 22, 2018 6:14 pm
Forum: Photoelectric Effect
Topic: Plastic vs Metal [ENDORSED]
Replies: 3
Views: 155

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?
by Shimran Kumar 1C
Sun Apr 22, 2018 6:08 pm
Forum: Significant Figures
Topic: Use of sigfigs
Replies: 8
Views: 361

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.
by Shimran Kumar 1C
Sat Apr 14, 2018 7:53 pm
Forum: Significant Figures
Topic: Sig Figs Multiplication [ENDORSED]
Replies: 3
Views: 222

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...
by Shimran Kumar 1C
Sat Apr 14, 2018 7:45 pm
Forum: Significant Figures
Topic: Sig Figs Multiplication [ENDORSED]
Replies: 3
Views: 222

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
by Shimran Kumar 1C
Sat Apr 14, 2018 7:36 pm
Forum: *Black Body Radiation
Topic: Black Body? [ENDORSED]
Replies: 13
Views: 1212

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 ...
by Shimran Kumar 1C
Sun Apr 08, 2018 9:44 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7582
Views: 1017376

Re: Post All Chemistry Jokes Here

I try to tell chemistry jokes, but there's no reaction :'(
by Shimran Kumar 1C
Sun Apr 08, 2018 9:38 pm
Forum: Ionic & Covalent Bonds
Topic: Types of Bonds
Replies: 10
Views: 377

Re: Types of Bonds

Can I apply a similar logic to ionic and metallic bonds? If so, what is it?
by Shimran Kumar 1C
Sun Apr 08, 2018 9:32 pm
Forum: Ionic & Covalent Bonds
Topic: Types of Bonds
Replies: 10
Views: 377

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.

Go to advanced search