Materials Science Homework - BIG PROBLEMS

[Iceman3]

I know there are set ways to post in this section, but I'm having so many problems with this class that I have to do it my own way. I decided to take Materials Science to help prepare me for graduate school and I am just struggling very much with this class. I haven't taken a physics class in 3 years, haven't taken a chemistry class in four. I have gone to talk to my professor, and he's useless to me. He doesn't explain anything, or even give me help, and so that doesn't do me any good. I've talked to a friend who graduated with a double major in Physics and Math and he said he was lost in this class so I'm a little nervous. I am asking for your help to help with me the basics because I seem to understand the newer stuff we've been doing much better. It's past my school's withdrawal period and I need to have the credits to graduate on time. I have had two homeworks, and I've been lost on both of them so I am hoping you guys can help me out a bit.

Here are the problems from Homework 1
1. Give the electron configurations for the following ions: P5+, P3-, and Ni2+.
2. What type(s) of bonding would be expected for each of the following materials: solid
xenon, bronze, and rubber?
3. Calculate the force of attraction between a Ca2+ and an O2- ion the centers of which
are separated by a distance of 1.25 nm.
4. Below are listed the atomic weight, density, and atomic radius for three hypothetical
alloys. For each determine whether its crystal structure is FCC, BCC, or simple cubic
and then justify your determination.
Alloy Atomic Weight (g/mol) Density (g/cm3) Atomic Radius(nm)
A 43.1 6.40 0.122
B 184.4 12.30 0.146
C 91.6 9.60 0.137

Here are the problems from Homework 2
5. A hypothetical AX type of ceramic material is known to have a density of 2.10 g/cm3
and a unit cell of cubic symmetry with a cell edge length of 0.57 nm. The atomic
weights of the A and X elements are 28.5 and 30.0 g/mol, respectively. On the basis
of this information, which of the following crystal structures is (are) possible for this
material: sodium chloride, cesium chloride, or zinc blende? Justify your choice(s).
6. Compute the atomic packing factor for the diamond cubic crystal structure (Fig.
3.16).
7. Sketch a monoclinic unit cell, and within that cell a [-101] direction.
8. Below are shown three different crystallographic planes for a unit cell of some
hypothetical metal. The circles represent atoms:(a) To what crystal system does the unit cell belong?
(b) What would this crystal structure be called?
(c) If the density of this metal is 18.91 g/cm3, determine its atomic weight.

**I've uploaded both Homeworks so you can see them if it makes it easier**

EDIT: any help, suggestions, links to learning places, would be fantastic. So far I haven't been able to do much learning with the way our course is taught (straight from PowerPoints) and I've been reading the book and taking notes. I just can't seem to wrap my head around crystal structures and so far that's what we've been doing. I would appreciate any help no matter how much or how little.

 

[KataKoniK]

Dear student,

I understand that you are facing difficulties with your Materials Science class and I am here to help you. I would like to offer some advice and suggestions to help you understand the concepts better.

Firstly, it is important to have a strong foundation in physics and chemistry before taking up Materials Science. Since you have not taken these classes in a while, I would recommend brushing up on the basics before diving into more complex topics. You can find online resources or textbooks to help you with this.

Secondly, I suggest reaching out to your professor again and explaining your struggles. Ask for specific examples or practice problems to work on and clarify any doubts you may have. If your professor is not able to provide you with the necessary help, consider seeking assistance from a teaching assistant or a tutor.

In addition, I would also recommend forming study groups with your classmates and discussing the concepts together. This can be helpful in understanding the material better and sharing different perspectives.

Regarding the specific problems from Homework 1 and 2, I would suggest going through your class notes and textbooks to understand the concepts related to electron configurations, bonding types, and crystal structures. You can also refer to online resources or watch videos on these topics to supplement your learning.

Lastly, I would like to remind you that it is okay to struggle with a class and it is important to not give up. Keep practicing and seeking help whenever needed. With determination and hard work, you will be able to understand the material and do well in your class.

I hope these suggestions are helpful to you. All the best for your studies.