Search found 47 matches

by Alondra Juarez section 1E
Sun Jun 10, 2018 10:40 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape of AX5E
Replies: 5
Views: 241

Re: Shape of AX5E

I believe that this would be a square pyramidal
by Alondra Juarez section 1E
Sun Jun 10, 2018 10:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: sigma and pi bond
Replies: 2
Views: 139

sigma and pi bond

I am quite confused on how to determine a sigma bond from a pi bond can anyone help?
by Alondra Juarez section 1E
Sun Jun 10, 2018 10:37 pm
Forum: Hybridization
Topic: basics of hybridization
Replies: 18
Views: 567

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).
by Alondra Juarez section 1E
Sun Jun 03, 2018 4:02 pm
Forum: Octet Exceptions
Topic: expanded octet
Replies: 12
Views: 449

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?
by Alondra Juarez section 1E
Sun Jun 03, 2018 3:59 pm
Forum: Lewis Structures
Topic: Electrons in Valence Shell
Replies: 4
Views: 178

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.
by Alondra Juarez section 1E
Sun Jun 03, 2018 3:58 pm
Forum: Lewis Structures
Topic: d-block Lewis structures
Replies: 3
Views: 175

Re: d-block Lewis structures

The process would be the same as a normal lewis structure count the electrons and draw accordingly.
by Alondra Juarez section 1E
Sun May 27, 2018 11:43 am
Forum: Electronegativity
Topic: Calculating electronegativity
Replies: 10
Views: 385

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.
by Alondra Juarez section 1E
Sun May 27, 2018 11:40 am
Forum: Dipole Moments
Topic: Polarization
Replies: 2
Views: 131

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.
by Alondra Juarez section 1E
Sun May 27, 2018 11:36 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Difference in bonds
Replies: 3
Views: 219

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?
by Alondra Juarez section 1E
Sun May 20, 2018 3:59 pm
Forum: Ionic & Covalent Bonds
Topic: double and triple bonds?
Replies: 2
Views: 68

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?
by Alondra Juarez section 1E
Sun May 20, 2018 3:56 pm
Forum: Ionic & Covalent Bonds
Topic: Formal charge?
Replies: 12
Views: 423

Formal charge?

What is formal charge and how do we calculate it?
by Alondra Juarez section 1E
Sun May 20, 2018 3:54 pm
Forum: Ionic & Covalent Bonds
Topic: Octet rule
Replies: 17
Views: 459

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.
by Alondra Juarez section 1E
Sun May 20, 2018 3:51 pm
Forum: Ionic & Covalent Bonds
Topic: Configurations
Replies: 4
Views: 143

Re: Configurations

You remove from the outermost electrons as they are the furthest away from the nucleus and require less energy to remove.
by Alondra Juarez section 1E
Sun May 13, 2018 11:36 am
Forum: Lewis Structures
Topic: formal charge?
Replies: 3
Views: 399

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.
by Alondra Juarez section 1E
Sun May 13, 2018 11:34 am
Forum: Lewis Structures
Topic: SO2
Replies: 5
Views: 306

Re: SO2

it would be more stable with two double bonds
by Alondra Juarez section 1E
Sun May 13, 2018 11:33 am
Forum: Lewis Structures
Topic: Order of Dots
Replies: 11
Views: 372

Re: Order of Dots

I believe they have to be balanced but it all corresponds to the number of electrons that element has
by Alondra Juarez section 1E
Sun May 06, 2018 5:24 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: electron configuration of chromium? [ENDORSED]
Replies: 3
Views: 176

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?
by Alondra Juarez section 1E
Sun May 06, 2018 5:21 pm
Forum: Trends in The Periodic Table
Topic: electronegativity
Replies: 4
Views: 129

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?
by Alondra Juarez section 1E
Sun May 06, 2018 5:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: half full?
Replies: 5
Views: 145

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?
by Alondra Juarez section 1E
Sun May 06, 2018 5:12 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 3d orbital
Replies: 3
Views: 127

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.
by Alondra Juarez section 1E
Sun May 06, 2018 5:06 pm
Forum: DeBroglie Equation
Topic: Calculating wavelength of an electron
Replies: 4
Views: 172

Re: Calculating wavelength of an electron

In order to calculate the wavelength you will use the equation λ=h/mv
by Alondra Juarez section 1E
Sun May 06, 2018 4:59 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Shapes of orbitals
Replies: 6
Views: 248

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
by Alondra Juarez section 1E
Mon Apr 30, 2018 4:06 pm
Forum: DeBroglie Equation
Topic: De Brogiles wavelength
Replies: 4
Views: 209

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...
by Alondra Juarez section 1E
Mon Apr 30, 2018 4:02 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra
Replies: 1
Views: 98

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 ...
by Alondra Juarez section 1E
Mon Apr 30, 2018 3:52 pm
Forum: Photoelectric Effect
Topic: light problem
Replies: 2
Views: 200

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...
by Alondra Juarez section 1E
Mon Apr 30, 2018 3:42 pm
Forum: Photoelectric Effect
Topic: Test 2 final question [ENDORSED]
Replies: 15
Views: 489

Re: Test 2 final question [ENDORSED]

it is a one to one ratio so it would be one thousand aswell.
by Alondra Juarez section 1E
Mon Apr 30, 2018 3:40 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 12
Views: 366

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.
by Alondra Juarez section 1E
Mon Apr 30, 2018 3:36 pm
Forum: Photoelectric Effect
Topic: What is work function? [ENDORSED]
Replies: 15
Views: 1041

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.
by Alondra Juarez section 1E
Sun Apr 22, 2018 1:19 pm
Forum: Properties of Light
Topic: 1.25 [ENDORSED]
Replies: 1
Views: 401

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?
by Alondra Juarez section 1E
Sun Apr 22, 2018 1:15 pm
Forum: Einstein Equation
Topic: constants [ENDORSED]
Replies: 2
Views: 120

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?
by Alondra Juarez section 1E
Sun Apr 22, 2018 1:11 pm
Forum: Properties of Light
Topic: frequency and wavelength [ENDORSED]
Replies: 5
Views: 198

frequency and wavelength [ENDORSED]

What is the relationship between frequency and wavelength how does one affect the other?
by Alondra Juarez section 1E
Sun Apr 22, 2018 12:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Test Number 1
Replies: 10
Views: 431

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.
by Alondra Juarez section 1E
Sun Apr 22, 2018 12:48 pm
Forum: Properties of Light
Topic: Speed of Light which is more accurate? [ENDORSED]
Replies: 6
Views: 181

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.
by Alondra Juarez section 1E
Sun Apr 22, 2018 12:40 pm
Forum: Properties of Light
Topic: Test 2 [ENDORSED]
Replies: 4
Views: 187

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.
by Alondra Juarez section 1E
Sun Apr 15, 2018 9:14 pm
Forum: Properties of Light
Topic: Equations [ENDORSED]
Replies: 8
Views: 181

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.
by Alondra Juarez section 1E
Sat Apr 14, 2018 9:04 pm
Forum: Properties of Light
Topic: formula for light problems
Replies: 2
Views: 95

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?
by Alondra Juarez section 1E
Sat Apr 14, 2018 8:28 pm
Forum: Properties of Light
Topic: help on the question from Fridays lecture [ENDORSED]
Replies: 2
Views: 85

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...
by Alondra Juarez section 1E
Sat Apr 14, 2018 8:22 pm
Forum: Properties of Light
Topic: wavelength description [ENDORSED]
Replies: 11
Views: 319

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...?
by Alondra Juarez section 1E
Sat Apr 14, 2018 8:17 pm
Forum: Limiting Reactant Calculations
Topic: Two limiting reactants?
Replies: 10
Views: 696

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.
by Alondra Juarez section 1E
Sat Apr 14, 2018 8:12 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical and Molecular Formulas [ENDORSED]
Replies: 4
Views: 164

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.
by Alondra Juarez section 1E
Sat Apr 14, 2018 8:09 pm
Forum: Significant Figures
Topic: Sig fifs in 750 [ENDORSED]
Replies: 6
Views: 350

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.
by Alondra Juarez section 1E
Sat Apr 07, 2018 5:54 pm
Forum: Balancing Chemical Reactions
Topic: How to know the state of the molecules [ENDORSED]
Replies: 6
Views: 233

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.
by Alondra Juarez section 1E
Sat Apr 07, 2018 5:22 pm
Forum: SI Units, Unit Conversions
Topic: why do I not use avogadro's number
Replies: 5
Views: 219

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...
by Alondra Juarez section 1E
Sat Apr 07, 2018 5:07 pm
Forum: Balancing Chemical Reactions
Topic: Balancing equations with fractions [ENDORSED]
Replies: 13
Views: 461

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...
by Alondra Juarez section 1E
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: 225

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...
by Alondra Juarez section 1E
Thu Oct 05, 2017 5:40 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Coefficients [ENDORSED]
Replies: 12
Views: 779

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.
by Alondra Juarez section 1E
Thu Oct 05, 2017 5:33 pm
Forum: SI Units, Unit Conversions
Topic: Molar Mass
Replies: 7
Views: 750

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.

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