## Materials Science C

bhavjain
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Posts: 153
Joined: February 20th, 2015, 7:30 pm
Division: C
State: PA

### Materials Science C

Short Event Description: Teams will answer a series of questions or complete tasks involving the science processes of chemistry focused in the areas of materials science.

What is Young's modulus a measure of, and what is its formula?
2017 Science Olympiad - (Invites TBD/Reg/State/Nats) - Division C

Anatomy: (-/-/-/-)
Astronomy: (-/-/-/-)
Disease Detectives: (-/-/-/-)
Ecology: (-/-/-/-)
Microbe Mission: (-/-/-/-)
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slowpoke
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Posts: 21
Joined: May 3rd, 2016, 4:59 pm
State: TX

### Re: Materials Science C

what is matsci
2017 R/S/N
Astronomy - 1/1/2
Chem Lab - 4/2/5
Hovercraft - 2/1/7
Materials Science - x/2/1

William P. Clements HS '17

bhavjain
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Posts: 153
Joined: February 20th, 2015, 7:30 pm
Division: C
State: PA

### Re: Materials Science C

what is matsci
Correct! Stess/strain can also be represented as $E = \frac{FL_0}{A_0\Delta L}$. Your turn.
2017 Science Olympiad - (Invites TBD/Reg/State/Nats) - Division C

Anatomy: (-/-/-/-)
Astronomy: (-/-/-/-)
Disease Detectives: (-/-/-/-)
Ecology: (-/-/-/-)
Microbe Mission: (-/-/-/-)
Remote Sensing: (-/-/-/-)
Rocks & Minerals: (-/-/-/-)
Towers: (-/-/-/-)

d4dd7y00n
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Posts: 8
Joined: December 8th, 2016, 4:13 am
Division: C
State: GA

### Re: Materials Science C

Short Event Description: Teams will answer a series of questions or complete tasks involving the science processes of chemistry focused in the areas of materials science.

What is Young's modulus a measure of, and what is its formula?
Young's modulus measures the elasticity of an object. The formula for Young's Modulus is stress/strain, or F/A/(delta(L)/L). A stands for the cross sectional of the object, and F is forced applied. L stands for the original length of an object, and delta L stands for change in length of the object.

hearthstone224
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Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

Can someone ask a new question, or should I ask a new one? I'll just ask one anyways.

What are Van der Waals Forces and what do they have to do with Materials Science?
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

hearthstone224
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Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

Eh, here's another good one. What kind of forces hold together Liquid Hydrogen?
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

Member
Posts: 66
Joined: January 6th, 2017, 4:51 pm
State: PA
Location: Swarthmore College

### Re: Materials Science C

Interesting...
Lower Merion 2017
Subtitled: Revenge of the Non-Harriton

Placement Record:

Code: Islip | Conestoga | Tiger | Regionals | States
Out of: 61 | 42 | 36 | 37 | 36

Chemistry Lab: 9 | - | - | 4 | 4
Astronomy: 14 | - | 5 | 10 | 3
Material Science: 12 | 19 | 9 | 5 | 9
Optics: 14 | 7 | 3 | 4 | 2

hearthstone224
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Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

The answer was Van der Waals which London Dispersion is a part of, so correct!

Can you explain why though? I was actually asking this for my own benefit too. I wasn't sure why the answer was LDF and so I wanted to know why.
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

Member
Posts: 66
Joined: January 6th, 2017, 4:51 pm
State: PA
Location: Swarthmore College

### Re: Materials Science C

In case someone wants to guess
And a question: Explain why CH4 is a gas at room temperature but C10H22 is a liquid.
Lower Merion 2017
Subtitled: Revenge of the Non-Harriton

Placement Record:

Code: Islip | Conestoga | Tiger | Regionals | States
Out of: 61 | 42 | 36 | 37 | 36

Chemistry Lab: 9 | - | - | 4 | 4
Astronomy: 14 | - | 5 | 10 | 3
Material Science: 12 | 19 | 9 | 5 | 9
Optics: 14 | 7 | 3 | 4 | 2

hearthstone224
Member
Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

In case someone wants to guess
And a question: Explain why CH4 is a gas at room temperature but C10H22 is a liquid.
Avogadro if I'm not mistaken, LDF's rely upon dipoles to form, right? Isn't LDFs between two induced dipoles for example maybe water molecules where electrons are shifted? I actually looked back and I realize that maybe the dipole-dipole could happen too since the dipoles are still there.

Either way, the answer would be van der waals forces (since all these interactions are counted as van der waals interactions.)

I looked online and this is my answer. Liquids become gases when the kinetic energy overcomes the attractive forces. CH4 has low attractive forces because it is first off tetrahedral, and because the bond is nonpolar covalent, meaning the electrons are shared evenly, there are no dipoles therefore cancelling out a lot of IMFs. Since it has very low attractive forces, it becomes a gas very easily.

On the other hand, C10H22 (decane) is a liquid because I'm assuming it has a lot more IMFs. It is a large chain structure and there is bound to be a lot of dipole interactions and London Dispersion forces going on.
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

hearthstone224
Member
Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

MY question (if I got it right):

Isomorphism is possible because of compatible

A) Ratio
B) Sizes
C) Shape
D) Color
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

Tom_MS
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Posts: 41
Joined: April 28th, 2015, 11:08 am
State: PA

### Re: Materials Science C

MY question (if I got it right):

Isomorphism is possible because of compatible

A) Ratio
B) Sizes
C) Shape
D) Color
Definitely B: Size. This is because the crystal structure of a given material is dependent on the radius of its atoms. Isomorphism means that two materials of different chemical composition have the same crystal structure. Ratio wouldn't really make sense because there is no hint at what the ratio would be comparing. The shape is more or less what isomorphism is, and color can be discarded immediately. This question has weird wording because it doesn't say what are the things that are compatible, but nevertheless, a worthwhile question to know the answer to.

hearthstone224
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Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

Correct! The answer is Size because isomorphism does mean the same shape! Therefore compatible sizes are possible.

Yeah, wording is a bit funky but its only an invitational question. Your turn!
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

Tom_MS
Member
Posts: 41
Joined: April 28th, 2015, 11:08 am
State: PA

### Re: Materials Science C

What is the name of the process by which a clay ceramic hardens under firing? Describe the microstructural changes of the ceramic during this process.

hearthstone224
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Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

What is the name of the process by which a clay ceramic hardens under firing? Describe the microstructural changes of the ceramic during this process.
I googled some info but I'm not sure what name you are referring to- most of the sites I found just called the process "firing".

I found that the water molecules inside the clay are being evaporated out and therefore when that happens the structure cannot return back to normal and its sort of "locked in place", and this change is called the ceramic change.
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.