## Search found 111 matches

Sun Oct 20, 2019 6:50 pm
Forum: Quantum Numbers and The H-Atom
Topic: Spin numbers
Replies: 4
Views: 63

### Re: Spin numbers

Electrons do spin, but the "up" and "down" -1/2 or +1/2 spin-orientation doesn't really matter, as long as you are consistent/mindfull of the antiparallel and parallel spinning. For more information, you should read this article: https://www.chemicool.com/definition/electron_spin...
Sun Oct 13, 2019 12:05 am
Forum: Photoelectric Effect
Topic: threshold energy
Replies: 6
Views: 58

### Re: threshold energy

In order for the electron to be excited it needs a very specific amount of energy. If it gets "too much" or "too little" it cannot move up to a certain energy level. For example, an electron needs a very specific amount of energy to go from the 1st energy level to the 2nd. Since ...
Sat Oct 12, 2019 11:59 pm
Forum: DeBroglie Equation
Topic: Learning Objective
Replies: 1
Views: 51

### Re: Learning Objective

This video does a really good job explaining it: https://www.youtube.com/watch?v=cYyFPFU6s_A
Sat Oct 12, 2019 11:57 pm
Forum: Photoelectric Effect
Topic: Mass of Electron
Replies: 6
Views: 64

### Re: Mass of Electron

In summary, electrons don't weigh a lot in comparison to protons or neutrons and thats why electron masses are "ignored" when thinking about molar masses. But since you asked electrons weigh about: 9.109×10−31 kilograms or 5.489×10−4 atomic mass units.
Sat Oct 12, 2019 11:54 pm
Forum: Properties of Light
Topic: wavelike properties
Replies: 6
Views: 56

### Re: wavelike properties

I'm not quite sure why electrons "need" to have wavelike properties, but I can say that through experimentation and mathematical models, scientists predict that electrons are a particle with wave-like properties.
Sat Oct 12, 2019 11:52 pm
Forum: Properties of Light
Topic: Large Objects
Replies: 7
Views: 83

### Re: Large Objects

Well if you take a look at the De Broglie's formula WaveLength = H/mass*velocity, as mass increases the wavelength is so small that it basically doesn't look or behave like a wave.
Tue Oct 01, 2019 8:44 pm
Forum: Limiting Reactant Calculations
Topic: Homework Problem M.5
Replies: 2
Views: 41

### Re: Homework Problem M.5

The problem: " Solve this exercise without using a calculator. The reaction 6 ClO2(g) + 2 BrF3(l) --> 6 ClO2F(s) + Br2(l) is carried out with 12 mol ClO 2 and 5 mol BrF 3 . (a) Identify the excess reactant. (b) Estimate how many moles of each product will be produced and how many moles of the e...
Tue Oct 01, 2019 8:32 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity Self test E1B
Replies: 2
Views: 40

### Re: Molarity Self test E1B

3.14 mols of H2O means there are 6.28 mols of Hydrogen.
6.28 mols * 6.022 *10^23 atoms/mol = 3.78*10^24 atoms
Tue Oct 01, 2019 8:30 pm
Forum: Molarity, Solutions, Dilutions
Topic: Dilution and Molarity Questions
Replies: 8
Views: 80

### Re: Dilution and Molarity Questions

Most dilution question, however wordy (or confusing the textbook might try to make it sound) they might be, come down to the M1 * V1 = M2 * V2 formula. I would try to make a list of the information given and then maybe what you don't know (which is usually just one variable) and then solve the equat...
Tue Oct 01, 2019 8:16 pm
Forum: Significant Figures
Topic: Rounding the elements
Replies: 12
Views: 157

### Re: Rounding the elements

I tend to round to the nearest whole number when I'm trying to come up with like a guesstimate or if I'm doing like a multiple-choice test. For homework or free-response questions on tests, I tend to use the number on the periodic table of elements (so 1.008 for H and 15.99 for O). I round/do sig fi...
Tue Oct 01, 2019 8:08 pm
Forum: Limiting Reactant Calculations
Topic: Problem G5
Replies: 2
Views: 77

### Re: Problem G5

A) The problem is asking "how much of the 250mL solution does the student need to obtain 2.15 mmol of Na+ ions?" 1. How many mols are in the 250 mL solution? a) Find molar mass of Na2CO3 which is 105.96 grams/mol b) 2.111g / 105.96g/mol = 0.0199 mols 2. Molarity of solution: 0.0199mols / 0...