CHEMISTRY COMMUNITY

Isobel Tweedt 1E

Just to be clear, they are less than because the loan electron pair pushes the other atoms farther away from it (and thus closer to other atoms). This then results in increasingly smaller angles between atoms as you move left to right along the chart.

Isobel Tweedt 1E

When using a strong acid our chemical equation can use a single arrow to show the reaction correct? This is because it is donating essentially all H+ protons?

Isobel Tweedt 1E

It's also important to remember that while acids always donate protons, Lewis acids accept pairs of electrons from Lewis base. Thus remember that acids donate protons but they can also accept thing (i.e. electron pairs).

Isobel Tweedt 1E

When determining hybridization is it always reliable to draw the lewis structure, determine the molecular shape, and then find the hybridization formula? What is the relationship between molecular shape and hybridization?

Isobel Tweedt 1E

In the case of linear shapes when a trigonal bipyramidal has 3 loan pairs or an octahedral has 4 loan pairs the bond angles are determined to be 180 degrees. How do loan pairs cause this?

Isobel Tweedt 1E

When determining pi bonds in double and triple bonds does it matter which bond is "selected" as the pi and sigma bonds?

Isobel Tweedt 1E

I was confused by this too, so here's a helpful website with images of what the bonds look like to demonstrate the different overlapping properties: https://sites.google.com/site/ed350201003/Task

Isobel Tweedt 1E

Also remember to address how bond strength is affected by resonance structures. For instance a double bond in a resonance structure is shorter (and thus stronger) than a regular double bond. This is because the actual structure is a combination of the resonance structures (and thus bonds).

Isobel Tweedt 1E

As a follow up, how do lone pairs affect bond angles? I understand that the lone pair sits more on top of the central atom - but does this always have the same affect on the angles?

Isobel Tweedt 1E

I'm still confused too, but it helps to see how covalently bonded atoms can become ionicly bonded cations or anions. Here's a helpful website:

https://www.diffen.com/difference/Coval ... onic_Bonds

Isobel Tweedt 1E

This also means that electronegativity and electron affinity follow the same periodic trends - increasing as you move up and to the right. This also means the atomic size is decreasing.

Isobel Tweedt 1E

Are there any elements that cannot only have one electron attached? Or are there any that are more likely to have just one in a lewis structure?

Isobel Tweedt 1E

How do valence electrons influence Lewis structures? Are they represented in any particular way?

Isobel Tweedt 1E

It helps to think of these in terms of a cation makes the ion "more positive" by removing electrons. Becuase an electron is negatively charged, removing it will make the element more positive. Correspondingly, an anion makes an element more negative by adding more electrons.

Isobel Tweedt 1E

Look at the group of the periodic table that the element is in. For example, Carbon is in group 4 and has 4 valence electrons.

Isobel Tweedt 1E

If you do have a high enough frequency (which in turn decreases the wavelength) then increasing the intensity will result in the release of more electrons. This is because more photons are hitting the metal and thus able to eject more electrons. As it says in the post above 10 photons that meet the ...

Isobel Tweedt 1E

I'm not sure I understand your whole question but here's some help on how to read the periodic table. If you look at the s-block there are only two columns, thus you can have 2s^1 2s^2 to get to Beryllium. So the 2 comes from row 2 and the ^1 and ^2 are the electrons (see columns). Similarly, in the...

Isobel Tweedt 1E

Another note on this topic - I asked my TA what happens when you remove a solute and if that changes the volume. She said that typically the change in volume would be so small we're not expected to calculate the density and correspodning change in volume. However, this calculation density = (mass)/(...

Isobel Tweedt 1E

Just to clarify the De Broglie equation does not work for objects without a rest mass (such as light). If you think about how light always has a constant speed it will never stop and thus never have a resting mass.

Isobel Tweedt 1E

Specifically, we know that the mass of an electron is 9.1095 x 10^-31 kg and the charge is 1.602 X 10^-19 coulombs. You can also find this on your formula sheet.

Isobel Tweedt 1E

Another important thing to note is that light always has the same constant speed (2.99792 x 10^8 m/s). This means any question about what speed light is traveling is actually really easy! Plus we should remember that light has no rest mass and thus cannot be used with the De Broglie equation. It's e...

Isobel Tweedt 1E

Is there ever a time we would look for a speed other than that of light? Or does this equation only ever use c?

Isobel Tweedt 1E

The basic equation c = fλ can be arranged as you would rearrange an equation in math. By moving around the variables you are keeping the equation the same, but making it easier to select for the unknown value you are trying to find. For instance, if I want to find the frequency of a wave I would use...

Isobel Tweedt 1E

Here's a helpful example of measuring a wavelength without using the peak to peak method. If you scroll down there's a great diagram in which the wavelength is measured from a different position on the wave!

https://tests.capnhq.gov/ops/archer_tra ... iation.cfm

Isobel Tweedt 1E

How does this relate to the concept of darkness versus lightness? Does the release of electrons result in our viewing of light and the color spectrum?

Isobel Tweedt 1E

v = c/ƛ so E = hc/ƛ

Isobel Tweedt 1E

To clarify, you square the amplitude to get the intensity of that wave.

Isobel Tweedt 1E

1. non zero = significant digit 1.234 has 4 2. zeros between two significant digits = significant digit 1.002 has 4 3. leading zeros = not significant digits 0.003 has 1 4. zeros following significant digits and a decimal = significant digits 300.0 has 4 0.0030 has 2 5. trailing zeros to the right o...

Isobel Tweedt 1E

Also just a note on working with molarity and liquids: when working with liquids the total solution volume changes (make sure to pay attention to the units your liquid is measured in). In this problem we are dealing with a 250ml flask and a solid solute (as seen with units grams) so the total volume...

Isobel Tweedt 1E

Can someone please clarify when we use molar mass versus atomic mass?

Isobel Tweedt 1E

When do I need to use Avogadro's Number?

CHEMISTRY COMMUNITY

Search found 31 matches

Re: Helpful Chart

Re: Oxoacids

Re: Donating electrons

Hybridization and Molecular Shape

Re: Lone pairs

Re: Pi bonds

Re: Types of Bonds

Re: Resonance

Re: Bond Angle

Re: Polarization

Re: Electronegativity vs. Electron affinity

Re: Radicals [ENDORSED]

Re: VALENCE ELECTRONS [ENDORSED]

Re: cation vs anion

Re: VALENCE ELECTRONS [ENDORSED]

Re: Frequency on Photoelectric Effect

Re: energy with s,p,d,f

Re: dilution

Re: Wavelength= (h/p) [ENDORSED]

Re: Mass of an Electron [ENDORSED]

Re: Equations for light [ENDORSED]

Re: Calculating wavelength [ENDORSED]

Re: Calculating wavelength [ENDORSED]

Re: Wavelength [ENDORSED]

Re: Threshold Energy [ENDORSED]

Re: Combining E=hv and c=ƛv [ENDORSED]

Re: Amplitude

Re: 300 vs 300. [ENDORSED]

Re: Module Assessment Question

Re: Molar Mass

Avogadro's Number