## Search found 14 matches

Sun Oct 28, 2018 10:42 pm
Forum: Trends in The Periodic Table
Topic: Trends in the periodic table
Replies: 2
Views: 117

### Re: Trends in the periodic table

Electron affinity generally increases from left to right and from bottom to top because the electrons added to the energy levels come closer to the nucleus, so theres a stronger attraction between the electrons and its nucleus.
Sun Oct 28, 2018 10:39 pm
Forum: Ionic & Covalent Bonds
Topic: Difference Between Ionic and Covalent Bonds
Replies: 4
Views: 155

### Re: Difference Between Ionic and Covalent Bonds

In ionic bonding, electrons are transferred from atoms A to atoms B. -It usually occurs between metals and nonmetals. -the nonmetals are "stronger" than the metals, so it can get electrons easily from the metal. -It has high polarity in covalent bonding, electrons are shared between atom C...
Sun Oct 28, 2018 9:29 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ionization Energy
Replies: 2
Views: 89

### Re: Ionization Energy

ionization energy is the energy required to remove an electron from its orbital.
so it would take a lot of energy to remove an electron from a full orbital (an octet) and it would take little energy to remove an orbital that only has 1 electron.
Sun Oct 21, 2018 11:48 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 2
Views: 62

### Electron Affinity

Can someone explain to me what it means to have high electron affinity?
Sun Oct 21, 2018 10:38 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Problem 1.43
Replies: 2
Views: 99

### Problem 1.43

(Problem 1.43) What is the minimum uncertainty in the speed of an electron confined to within a lead atom of diameter 350. pm? Model the atom as a one-dimensional box with length equal to the diameter of the actual atom.

In the problem is h a constant? I don't understand why we need to solve for h.
Sun Oct 21, 2018 7:32 pm
Forum: Properties of Light
Topic: Test #2
Replies: 2
Views: 107

### Test #2

Is the test going to take place during discussion?
Tue Oct 09, 2018 8:19 pm
Forum: Molarity, Solutions, Dilutions
Topic: Homework problem G5
Replies: 2
Views: 308

### Re: Homework problem G5

To find the volume, you have to use the n/V= c equation, or in other words, the # moles divided by the volume gives you the molarity. For Part a) you find the molarity of Na2CO3 and you are given the moles of Na+ which is 0.00215 mol Na. To find the volume, you have to divide the number of moles (0....
Tue Oct 09, 2018 8:08 pm
Forum: SI Units, Unit Conversions
Topic: Preferred Units for Tests and Homework
Replies: 3
Views: 158

### Re: Preferred Units for Tests and Homework

I do not think it matters because they essentially mean the same thing.
Tue Oct 09, 2018 8:02 pm
Forum: SI Units, Unit Conversions
Topic: Conversions
Replies: 2
Views: 93

### Conversions

For Problem L35, it asks for the mass of Fe that is needed to produce 2.5 t of NaBr, but what is "t"? I've never seen that unit of measure.
Thu Oct 04, 2018 1:05 am
Forum: Molarity, Solutions, Dilutions
Topic: 6th Edition, Question E.25b
Replies: 1
Views: 68

### Re: 6th Edition, Question E.25b

When converting number of atoms, ions, molecules to moles you must use Avogadro's constant (6.022 X 10^23 mol-1)
so 2.39 X 10^20 formula units of Ag2SO4 must be divided by Avogadro's constant.
Thu Oct 04, 2018 12:46 am
Forum: Student Social/Study Group
Topic: Percent Composition
Replies: 3
Views: 337

### Re: Percent Composition

Mass percentage composition is found by calculating a fraction of the total mass by each element present in a compound. The whole compound itself would would equal 1 or 100% and all the elements that make it up would only be a fraction, so it will always have to add up to 100%. Try checking if you a...
Thu Oct 04, 2018 12:32 am
Forum: Limiting Reactant Calculations
Topic: Homework Questions [ENDORSED]
Replies: 4
Views: 111

### Re: Homework Questions[ENDORSED]

In the syllabus it says that you can choose any 7 problems and does not specify that you have to choose problems from all sections. I believe they just endorse that you try problems from all sections so that you could improve your own skills.
Thu Oct 04, 2018 12:26 am
Forum: Molarity, Solutions, Dilutions
Topic: Problem G5
Replies: 8
Views: 241

### Re: Problem G5

Start out by finding the molarity of NaCO3: -find out the moles of NaCO3: (2.111 g NaCO3) / (105.99 g/mol) = 0.01992 mol -find out the molarity: (0.01992 mol) / (.250 mL) =.0796 For Part A, because for every mole of Na2CO3 you have 2 moles of Na+, you have to multiply the molarity of NaCO3 (0.0796) ...
Wed Oct 03, 2018 11:12 pm
Forum: Limiting Reactant Calculations
Topic: Fundamental M.9 [ENDORSED]
Replies: 3
Views: 125

### Re: Fundamental M.9[ENDORSED]

A net ionic equation is a chemical equation that only shows elements, compounds, or ions that are directly involved in the chemical reaction. So when you write out the ionic equation for NaOH + Cu(NO3)2 --> Cu(OH)2 + NaNO3 : Cu2+ + 2NO3- + 2Na+ + 2OH- ---> Cu(OH)2 + 2Na+ + 2NO3- Since 2Na+ and 2NO3-...