Search found 30 matches

by Komal Prakash 1H
Mon Jun 11, 2018 12:57 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Homework Question 4.73
Replies: 1
Views: 165

Re: Homework Question 4.73

Lone pairs exert a force on the bonds that pushes them further to create an angle less that 109.5 degrees. Lone-lone pair repulsion is the strongest, followed by lone-bonding pair, and then bonding to bonding pair. In the case of CH2^2- and CH3^-, CH2^2- has an extra lone pair in comparison to CH3^-...
by Komal Prakash 1H
Mon Jun 11, 2018 12:48 am
Forum: Sigma & Pi Bonds
Topic: pi and sigma bonds
Replies: 2
Views: 213

Re: pi and sigma bonds

Sigma bonds are stronger and harder to break than pi bonds. Sigma bonds are a result of the head-on overlapping of orbitals while pi bonds are the result of the side-by-side overlap of orbitals. Thus, pi bonds are weaker because the electrons are further apart and sigma bonds have more overlapping a...
by Komal Prakash 1H
Mon Jun 11, 2018 12:44 am
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 9
Views: 379

Re: Bond Length

As the response above me was getting at, remember that with decreases bond length you have increasing bond strength. We know that triple bonds have the largest bond strength and so they have the the shortest bond length.
by Komal Prakash 1H
Mon Jun 04, 2018 12:38 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs
Replies: 5
Views: 177

Re: Lone pairs

Also, lone pairs of one atom can repel lone pairs of neighboring atoms as well as bonding electrons. However, the repulsion strength is larger when lone pairs repel other lone pairs than when a lone pair repels a bonding electron (however, lone to bonding is the most common as causes a slight change...
by Komal Prakash 1H
Mon Jun 04, 2018 12:30 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Problem 4.27
Replies: 4
Views: 152

Re: Problem 4.27

First off, because C2H6 is made of only C and H, you can look at the difference in electronegativities between C and H. Since H has about a 2.22 electronegativity and C has an electronegativity of 2.55, the difference is less than 0.5, so the bond is usually then nonpolar. We also see that the lewis...
by Komal Prakash 1H
Mon Jun 04, 2018 12:12 am
Forum: Hybridization
Topic: Sigma Bonds
Replies: 5
Views: 174

Re: Sigma Bonds

Sigma bonds are the covalent bonds formed as a result of the head-on overlapping of orbitals while pi bonds are the covalent bonds formed by the side-by-side overlap of orbitals. Sigma bonds are also stronger that pi bonds. Basically, you should know that a single bond has 1 sigma bond, double bond ...
by Komal Prakash 1H
Sun May 27, 2018 10:00 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Charged Molecule
Replies: 2
Views: 207

Re: Charged Molecule

Thus, the procedure for finding the formal charges of each atom will be the same; however, when those calculated formal charges are added up, they will add up to the charge of the molecule rather than zero or some other low number.
by Komal Prakash 1H
Sun May 27, 2018 9:53 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing Power
Replies: 3
Views: 205

Re: Polarizing Power

A cation's polarizing power is what allows it to distort the shape of another atom. The larger the charger the greater the polarizing power because it can pull more stronger on the electrons of the other atom. Furthermore, the bigger the size the SMALLER the polarizing power because bigger atoms hav...
by Komal Prakash 1H
Sun May 27, 2018 9:49 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarity
Replies: 2
Views: 191

Re: Polarity

In addition to larger atoms having more polarizability, atoms with less electronegativity are more polarizable because atoms with larger electronegativities want more electrons and so they hold onto their electrons more tightly. Thus, when categorizing atoms in increased polarizability, you first lo...
by Komal Prakash 1H
Sun May 27, 2018 9:42 pm
Forum: Lewis Structures
Topic: Ionic Compounds
Replies: 2
Views: 120

Re: Ionic Compounds

Also, usually ionic compounds occur when nonmetals and metals exchange electrons while covalent bonds are the sharing of electrons between two nonmetals. This will allow you to look at the types of elements involved in the compound and figure out what type of bond is occurring between them.
by Komal Prakash 1H
Sun May 27, 2018 9:36 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Difference in bonds
Replies: 3
Views: 238

Re: Difference in bonds

When you are looking at comparing two of the same bond type (like two triple bonds), you can figure out which is longer and weaker by factoring in the radius of the atoms involved. Atoms with a larger radius will make the bond longer and as a result weaker (and vice versa, smaller radius=smaller bon...
by Komal Prakash 1H
Sun May 27, 2018 9:32 pm
Forum: Lewis Structures
Topic: Multiple Compounds (3.41)
Replies: 3
Views: 103

Re: Multiple Compounds (3.41)

When making Lewis structures, it also helps to put the least electronegative atoms in the center and to look at how many valence electrons an atom has. The more it has, the less central in the structure it probably is because it has less electrons to be filled.
by Komal Prakash 1H
Sun May 13, 2018 9:55 pm
Forum: Quantum Numbers and The H-Atom
Topic: xyz
Replies: 2
Views: 218

Re: xyz

So the principle quantum number, n, tells you the number of shells. The angular quantum number, l, tells you the subshell and orbital types (so s, p, d, or f, etc). The magnetic quantum number (ml) tells you the different orientations of the orbitals of that orbital type. For example, the p orbital ...
by Komal Prakash 1H
Sun May 13, 2018 9:47 pm
Forum: Lewis Structures
Topic: Lower formal charges
Replies: 2
Views: 70

Re: Lower formal charges

I believe it is because atoms want to reach a lower state of energy when they bind to one another. So more stable structures have smaller individual formal charges. Thus, when finding the actual Lewis structure of a compound, you should try to draw Lewis structures of each atom with a formal charge ...
by Komal Prakash 1H
Sun May 13, 2018 9:33 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: cations
Replies: 5
Views: 188

Re: cations

As you move from left to right on a periodic table, the number of protons is increasing but the number of shells stays the same (n). Thus, the increase in protons increases the effective nuclear charge on the electrons and pulls them in tighter, so both atomic and ionic radius decrease as you move f...
by Komal Prakash 1H
Tue May 08, 2018 2:50 am
Forum: Trends in The Periodic Table
Topic: Ionization Energy (2.61) [ENDORSED]
Replies: 2
Views: 145

Re: Ionization Energy (2.61) [ENDORSED]

As explained above, first ionization energy is the energy required to move the first electron. Thus, when working with questions like in the example, when choosing which has the smaller first ionization energy you have to consider which one is more stable. The more stable elements have more fully oc...
by Komal Prakash 1H
Tue May 08, 2018 2:42 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2.29
Replies: 3
Views: 191

Re: 2.29

The number of ml values tell you the total number of orbitals in the atom and each orbital can hold 2 electrons, so 2 times the number of orbitals will tell you the maximum number of electrons that can occupy a certain subshell.
by Komal Prakash 1H
Tue May 08, 2018 2:36 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.59
Replies: 2
Views: 136

Re: 2.59

They would not be the same because as you move from left to right on the periodic table, ionic radius decreases. This is because as you move from left to right, the number of protons and thus effective nuclear charge increases which draws the electrons closer and so the Cl- ion will have the smalles...
by Komal Prakash 1H
Mon Apr 30, 2018 12:01 am
Forum: Properties of Electrons
Topic: Is this movement noticeable?
Replies: 4
Views: 215

Re: Is this movement noticeable?

The idea is not really that those big objects don't show movement but that objects with really small masses show measurable wavelike properties. Objects like a car or ball do not have a small enough mass for the wavelength to be small enough to show such properties.
by Komal Prakash 1H
Sun Apr 29, 2018 11:58 pm
Forum: Einstein Equation
Topic: p=mv [ENDORSED]
Replies: 3
Views: 317

Re: p=mv [ENDORSED]

I think when you say power you mean momentum and p=mv stands for momentum=mass times velocity. The work function is the energy required to eject an electron from a metal surface so it is not interchangeable with momentum (momentum is different from energy, which is in joules).
by Komal Prakash 1H
Sun Apr 29, 2018 11:48 pm
Forum: Trends in The Periodic Table
Topic: S and d orbitals [ENDORSED]
Replies: 2
Views: 83

Re: S and d orbitals [ENDORSED]

4s orbitals have a lower energy than 3d orbitals, so the 4s orbital fills up before the 3d orbital (you fill up lower energy orbitals before the higher energy ones).
by Komal Prakash 1H
Mon Apr 23, 2018 12:04 am
Forum: Properties of Light
Topic: Wave and Particle
Replies: 10
Views: 386

Re: Wave and Particle

I believe that one photon is a particle of light, but a stream of photons results in a wave of light.
by Komal Prakash 1H
Mon Apr 23, 2018 12:00 am
Forum: Properties of Light
Topic: Memorizing formulas test 2
Replies: 16
Views: 582

Re: Memorizing formulas test 2

It does help to know the units of the equations. However, if you know the SI units for each variable, then you can use the relationships as shown in the equation given to find the resulting units.
by Komal Prakash 1H
Sun Apr 22, 2018 11:58 pm
Forum: DeBroglie Equation
Topic: De Brogile's equation [ENDORSED]
Replies: 4
Views: 223

Re: De Brogile's equation [ENDORSED]

We cannot use the De Brogile's equation for light, because wavelength=h/momentum, and momentum equals mass times velocity. Since photons do not have a mass, momentum would be zero, and we cannot divide by zero.
by Komal Prakash 1H
Wed Apr 18, 2018 9:36 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Equation
Replies: 7
Views: 517

Re: Balancing Equation

If the balancing question is not easy enough to just guess and check then you can use a method where you assign a variable to each unknown coefficient and then make a system of equations for how many times each element appears and solve the system. For example, in __a_KClO3+__b_C6H12O6+__c__KCl+__d_...
by Komal Prakash 1H
Wed Apr 18, 2018 9:27 pm
Forum: Photoelectric Effect
Topic: Chapter 1 HW problem 33
Replies: 1
Views: 99

Re: Chapter 1 HW problem 33

The SI unit for wavelength is meters, so you need to convert the km/s in the velocity into m/s. This is done by multiplying the given velocity by 1000 m or 10^3m (1000m in 1km). This will give you a velocity of 3.6x10^6 m/s and in the final solution you will get the correct answer.
by Komal Prakash 1H
Wed Apr 18, 2018 9:19 pm
Forum: DeBroglie Equation
Topic: Midterm Question: wavelike properties
Replies: 6
Views: 297

Re: Midterm Question: wavelike properties

In lecture today, Dr. Lavelle shared that in order for something to have measurable wavelike properties, it must have a wavelength bigger than 10^(-18)m. Thus, as described in class, a car would not have measurable wavelike properties as, in the example, its wavelength = 1.64x10^(-38)m. However, an ...
by Komal Prakash 1H
Wed Apr 18, 2018 9:10 pm
Forum: Properties of Light
Topic: Speed of light constant
Replies: 5
Views: 183

Re: Speed of light constant

The speed of light constant, c, will be provided to us as previously mentioned and can be used in a variety of problems. We recently have also begun to conduct calculations using E= h x v as well as En= (-h x R)/(n^2). These questions often give us energy levels that electrons transition from and re...
by Komal Prakash 1H
Wed Apr 18, 2018 8:58 pm
Forum: Properties of Electrons
Topic: electron mass
Replies: 15
Views: 567

Re: electron mass

The small mass of an electron is significant as it allows us to observe the wavelike properties of an electron even when it is traveling at high speeds (even as the speed gets closer to the speed of light, the mass is so small that the wavelength=(h/(mass X velocity)) is observable.
by Komal Prakash 1H
Wed Apr 18, 2018 8:52 pm
Forum: Properties of Light
Topic: Series Question
Replies: 3
Views: 113

Re: Series Question

Basically what characterizes one series from the other is which energy level the electrons fall to. In the Lyman series, which is the UV spectrum, electrons fall from other, higher energy levels to n=1, while in the Balmer series, visible light, electrons fall to n=2 and no lower (and so on).

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