## Search found 34 matches

Sun Nov 29, 2020 11:58 pm
Forum: Significant Figures
Topic: Sig Fig Question
Replies: 12
Views: 72

### Re: Sig Fig Question

Yes you are correct. The reason there is a decimal after the 350. is to indicate 3 Sigfigs and not 2.
Sun Nov 29, 2020 11:54 pm
Forum: Significant Figures
Replies: 5
Views: 26

Yes, you have it right. When mulitiplying you would use the least number number of Sigfigs and when adding you would use the least number of Sigfigs after the decimal.
Sun Nov 29, 2020 11:50 pm
Forum: Significant Figures
Topic: 0's
Replies: 21
Views: 120

### Re: 0's

When there is a decimal point the trailing points are counted. Therefore, 20.00 has 4 SigFigs.
Sun Nov 29, 2020 11:44 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 12
Views: 79

### Re: Sig Figs

We should always use SigFigs in our answer I believe. It's handy in most situations.
Sun Nov 29, 2020 11:34 pm
Forum: Significant Figures
Topic: 40. versus 40
Replies: 23
Views: 60

### Re: 40. versus 40

The decimal makes 40. have two sigfigs. Without the decimal it just has one sigfig.
Sun Nov 22, 2020 9:50 pm
Forum: Lewis Structures
Topic: Central Atom Question
Replies: 20
Views: 70

### Re: Central Atom Question

H can not be a central atom because it can only form one chemical bond.
Sun Nov 22, 2020 9:49 pm
Forum: Lewis Structures
Topic: Lewis acids and bases
Replies: 23
Views: 56

### Re: Lewis acids and bases

A Lewis acid would accept electrons while a Lewis base would donate electrons.
Sun Nov 22, 2020 9:47 pm
Forum: Molarity, Solutions, Dilutions
Topic: mmol
Replies: 14
Views: 118

### Re: mmol

The unit mmol is a millimole. It is 10^-3 of a mol.
Sun Nov 22, 2020 9:46 pm
Forum: SI Units, Unit Conversions
Topic: unit conversions
Replies: 13
Views: 118

### Re: unit conversions

I agree with many of the people in this post. Keeping it in scientific notation will be best for consistency in calculations, and it keeps the answer in sigfigs.
Sun Nov 22, 2020 9:42 pm
Forum: SI Units, Unit Conversions
Topic: Modules This Week
Replies: 9
Views: 57

### Re: Modules This Week

I don't believe there are any more modules for future topics. However, I do agree that they are very helpful in going back and studying material.
Sun Nov 15, 2020 11:29 pm
Forum: SI Units, Unit Conversions
Topic: picometer conversion
Replies: 13
Views: 71

### Re: picometer conversion

In order to convert meters into picometers you would multiply by 1 * 10^-12.
Sun Nov 15, 2020 10:54 pm
Forum: Properties of Electrons
Topic: intensity vs energy
Replies: 26
Views: 134

### Re: intensity vs energy

The answer is false because increasing intensity increases the number of photons. Energy only increases when frequency increases.
Sun Nov 15, 2020 10:17 pm
Forum: Properties of Light
Topic: Is c always the speed of light?
Replies: 72
Views: 255

### Re: Is c always the speed of light?

Yes, I do believe that the speed of light will always be represented as the constant c.
Sun Nov 01, 2020 9:27 pm
Forum: Properties of Electrons
Topic: Sapling 6
Replies: 3
Views: 25

### Re: Sapling 6

Your equation looks right, so I would make sure you put everything into your calculator right. I would also make sure you converted the frequency into wavelength right using lambda = c/f. Then change the wavelength into nanometers.
Sun Nov 01, 2020 9:24 pm
Forum: Einstein Equation
Topic: Sapling #1
Replies: 6
Views: 67

### Re: Sapling #1

The equation E=hv gives the energy per photon. So that's why it is 100E. Wavelength and frequency are not affected because each photon would have its own frequency and wavelength. Since each photon has the same energy, they would have the same wavelength and frequency keeping it a 1.
Sun Nov 01, 2020 9:20 pm
Forum: Properties of Light
Topic: How to remember what v is in equations
Replies: 46
Views: 142

### Re: How to remember what v is in equations

The italicized v is actually the Greek letter nu and is used for frequency. When working with velocity it is just a regular v.
Sun Nov 01, 2020 9:17 pm
Forum: Properties of Light
Topic: Sapling 19
Replies: 6
Views: 61

### Re: Sapling 19

In order to solve this problem, you would need to use the de Broglie equation. The problem is asking for the velocity of each so you would need to isolate velocity.

wavelength = h/mv

v=h/m(wavelength)
Sun Nov 01, 2020 9:13 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Sapling #24
Replies: 16
Views: 67

### Re: Sapling #24

You have to make sure that the wave ends in the same position where it begins. For example, if the wave ends at the midway point going up then the beginning of the wave would have to start at the midway point going up. It would have to be continuous if connected.
Sun Oct 25, 2020 9:11 pm
Forum: Properties of Light
Topic: Balmer or Lyman Series
Replies: 9
Views: 47

### Re: Balmer or Lyman Series

The Balmer series ends at n=2 and the Lyman series ends at n=1. The Lyman series deals with UV light and the Balmer series deals with visible light. This is helpful when you don't know exactly where it ends, but it gives you what kind of light you are dealing with.
Sun Oct 25, 2020 9:03 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: for test 1
Replies: 14
Views: 188

### Re: for test 1

I don't believe that we will be asked a question about the definition of those words exactly. However, it will probably be useful to know what these words mean because they could be used in a question on the test.
Sun Oct 25, 2020 8:56 pm
Forum: Balancing Chemical Reactions
Topic: Periodic Table
Replies: 50
Views: 412

### Re: Periodic Table

We will not have to memorize elements on the periodic table. We will given the periodic table on Lavelle's website to use during tests.
Sun Oct 25, 2020 8:49 pm
Forum: Significant Figures
Topic: How would you round these numbers
Replies: 10
Views: 82

### Re: How would you round these numbers

Rounding those numbers to 8.0 and 5.0 would be correct. Zeroes following a number 1-9 count as a significant figure when there is a decimal.
Sun Oct 25, 2020 8:45 pm
Forum: SI Units, Unit Conversions
Topic: units to know for midterm
Replies: 11
Views: 114

### Re: units to know for midterm

My TA let us know that we can print out the constants and equations sheet on Professor Lavelle's website for the test. We can also print out the periodic table on his website to use on the test.
Sun Oct 18, 2020 11:47 pm
Forum: Balancing Chemical Reactions
Topic: Syntax Question
Replies: 4
Views: 32

### Re: Syntax Question

Yes, (OH)2 would be the same as writing O2H2. Adding parenthesis just groups them together and simplifies the term.
Sun Oct 18, 2020 11:44 pm
Forum: Photoelectric Effect
Topic: Frequency vs. Intensity
Replies: 16
Views: 100

### Re: Frequency vs. Intensity

Increasing the intensity will only increase the number of photons, but not the energy. So increasing intensity will not give it enough energy to eject electrons. However, increasing the frequency will increase the energy of the photon. Therefore, increasing frequency can give it the energy needed fo...
Sun Oct 18, 2020 11:27 pm
Forum: SI Units, Unit Conversions
Topic: unit conversions
Replies: 13
Views: 118

### Re: unit conversions

I think the best way is just to do 10^x. It also keeps it in scientific notation for sigfigs.
Sun Oct 18, 2020 11:16 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Preference on Scientific Notation
Replies: 11
Views: 101

### Re: Preference on Scientific Notation

In writing scientific notation, I would use the * 10^x notation. I feel like the E6 is great for typing things into the calculator tho.
Sun Oct 11, 2020 9:33 pm
Forum: Empirical & Molecular Formulas
Topic: Calculation Errors for Empirical Formulas
Replies: 10
Views: 61

### Re: Calculation Errors for Empirical Formulas

I believe that 2.8 is close enough to 3 to round up. I believe that the bench marks are whole numbers, .25, .33, .5, .67, and .75. So with a 2.8 you would not round down to 2.75, it makes sense to just round up to 3.
Sun Oct 11, 2020 9:22 pm
Forum: Balancing Chemical Reactions
Topic: Order of Balancing Rxns
Replies: 23
Views: 104

### Re: Order of Balancing Rxns

For Balancing Rxns, I usually try to balance metals first. Then I would balance carbon. If hydrogen and oxygen are in the equation, I would balance hydrogen next and oxygen last always. I try to stick to this most of the time.
Sun Oct 11, 2020 8:59 pm
Forum: Significant Figures
Topic: SigFigs
Replies: 4
Views: 42

### SigFigs

I had a question about Significant Figures with decimals. When there is a decimal, do all leading zeroes not count towards SigFigs? For example, would 0.0840 be 5 SigFigs or 3 SigFigs?

Thank you!
Sun Oct 11, 2020 8:46 pm
Forum: SI Units, Unit Conversions
Topic: Kg to g
Replies: 13
Views: 105

### Re: Kg to g

Hi Alessia! In order, to convert Kg to g you have multiply your number by 1000. For example, if you have 25 Kg then to convert that to grams you would multiply 25 by 1,000. Therefore you would get 25,000 grams. I hope this helps!
Wed Oct 07, 2020 9:52 am
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 226
Views: 116479

### Re: Advice from a Medical Student[ENDORSED]

Tue Oct 06, 2020 1:41 pm
Forum: Molarity, Solutions, Dilutions
Topic: Sapling Question 6 Homework 1
Replies: 3
Views: 38

### Re: Sapling Question 6 Homework 1

I totally converted liters to milliliters wrong, thank you guys!
Tue Oct 06, 2020 1:33 pm
Forum: Molarity, Solutions, Dilutions
Topic: Sapling Question 6 Homework 1
Replies: 3
Views: 38

### Sapling Question 6 Homework 1

The problem is, "If 3.16 g of CuNO3 is dissolved in water to make a 0.400 M solution, what is the volume of the solution in millimeters?" First, I found the molar mass of CuNO3 and got 125.553 g/mol. I then divided 3.16g by 125.553g/mol to get 0.0252 mol CuNO3. I then found the equation fo...