Solids Definition and 313 Threads

Dear Forum, I know that in a solid molecules have a more compact organization. Are molecules arranged in a periodic structure, i.e. a crystal, in all solids? Do all solid have a crystalline organized structure? Polymers exhibit crystal organization of the same type only over small finite...

I sort of new to the states of matter, so please use English (explain what all the big words mean). First of all what does ionizing even mean? second every type of matter of 4 states?

Homework Statement Below is an image of a unit cell for MgO. Does MgO have the lattice structure of NaCl or ZnS? If the density of MgO, ##\rho## = 3,58g/cm3, evaluate the sizes of the radii of Mg2+- and O2--ions. Answers: 149pm and 62pm Homework EquationsThe Attempt at a Solution Looking...

I just now read in my textbook that solids and liquids are not included in equilibrium expressions, are they included in rate laws? If not, why? Would a greater molar amount of solid or liquid increase the rate of reaction? And why isn't surface area included in Rate Laws? Also, for the...

I've been trying to figure out why you can't use the average value of a function to determine the volume of a solid of revolution. As an example: Trying to find the volume of a solid of revolution on y=√x from 0 to 1 around the x-axis. The definite integral is 2/3, which divided by one is...

I was working on a problem on this domain: E=[x,y,z)\:s.t. \: \sqrt{x^2+y^2}\leq z\leq \sqrt{3x^2+3y^2},\: x^2+y^2+z^2\leq 2] and at some point I wanted to find the intersection of the internal cone(##\sqrt{3x^2+3y^2}=z##) with the sphere of radius ##\sqrt{2}## to find the height z of the...

Hello everyone, First of all thank you for your help. I'd like to know if there are any ph testers for solids not diluted and where can I buy them and how much would they cost. Thanks!

So there was this question: Which sample demonstrates particles arranged in a regular geometric pattern? A. CO2(g) B. CO2(s) C. CO2(l) D. CO2(aq) E. None of the above I chose E because I thought that covalent molecules, when solid, would be arranged in a random pattern, especially since this...

I'm thinking of taking a course called Atoms, Molecules, and Solids this semester and I wanted to get a feel for the material beforehand to see if I'll like the course. If anyone could recommend a textbook based off this course description, I'd appreciate it: Quantum theory of atoms...

Hello all, - first of all sorry for my bad english, it's not my mother tong. - I write here because I want to understand that are the surface waves and how can we demonstrate their existence ? Do you have a PDF file which speak about this ? - For volumic waves I have seen a mathematical...

Homework Statement I understood the fact that since the density of solids and liquids remain constant in a reaction therefore the active mass must be a constant.But why is it that we take it as unity. Is is some kind of coonverntion,or is there a reason behind it? Homework EquationsThe Attempt...

Homework Statement The problem I have been set is to rework the Drude model using clearly defined scattering statistics. Homework Equations The Drude model as we have been given it is in terms of momentum \vec{p}(t+dt)=(1-\frac{dt}{\tau})(\vec{p}(t)-q\vec{E}(t)dt)+(\frac{dt}{\tau})(0) Where...

Homework Statement : A cylinder is elongated by 2% of its original length. If Poisson's ratio of its material is 0.3. Calculate the percentage variation in volume.[/B]Homework Equations V = πr^2l η= 0.3= Δl/l/Δr/r[/B]The Attempt at a Solution I tried using calculus to differentiate V to find...

Hello all, i have been asked a question about a lump of iron being warmed, and to calculate the difference between enthalpy and internal energy. I did some algebra and found that the change in the product pV , in the case of a liquid would suffice. But, since the volume doesn't change (Assumed...

Hi everybody! Lately I tried to overcome some problems with understanding thermodynamics laws, and unfortunately I couldn't find anything about my question:nb) and I really hope someone can help me here... My question is: This version of Gibbs formula dG= VdP-SdT, can be applied to any close...

Say, I have 10 Km (1m dia.) exposed pipeline under construction phase. 9 Km of the pipe line was already done. Its so happen that at the next pipe length installation, the plane operator mishandled the pipe and it collided at the end where connection should be made, big time that the magnitude...

Do electrons in conduction band are only responsible for current? Don't the electrons in partially filled valence band capable of moving contribute to current? Material discussed-metals(conductors)

Consider the figure from section "Electrical conductivity":https://en.wikipedia.org/wiki/Valence_and_conduction_bands I understand that below the Fermi level, we have bands of allowed energy separated by band gaps. Then, we have the Fermi level. Then we have the conduction band. My question...

I'm looking for a way to calculate the probabilities of Archimedean Solids landing on a specific face if a person would roll one. Of course, not the regular polygons like cubes and dodecahedrons, but something with more than one type of face like the snub cube or truncated icosahedron. I am...

Homework Statement Sketch the solid whose spherical coordinates (ρ, φ, θ): 0≤ρ≤1, 0≤φ≤(pi/2) Homework EquationsThe Attempt at a Solution I was thinking that since ρ represented the distance from the point of the origin and φ represented the angle between the positive z-axis and the ray through...

I have a few questions about finding volumes of solids of revolution (in a typical first year single variable calculus course). 1) I can rotate any region about any horizontal/vertical axis. How exactly do I rotate a region about a line that is neither horizontal nor vertical (##y = x - 1## for...

Hi all, I'm brushing up on some thermodynamics, and having been reading up on the interpretation of temperature as derived from kinetic theory. I can follow the derivation for an ideal, monatomic gas which relates temperature to the average, translational kinetic energy of the molecules. Most...

Hi! I feel like I've understood none of this stuff! A 1D chain of springs and masses modeling a chain of atoms has a dispersion relation ala ## \omega## ~ ##|sin(k a /2) |##, where ##k## is the wave vector and ##a## the distance between atoms. As far as I have understood, the debye model (in...

Homework Statement I'm having trouble figuring out if a solid is a molecular solid or network covalent solid. Classify the following as a network covalent solid or a molecular solid: 1. CO2 2. SiO2 Homework Equations Molecular solid held together by intermolecular forces Covalent network...

molecular solids are bonded intramolecularly by: 1_primary bonds 2_secondary 3_van der waals 4_all of them

Homework Statement 2. Homework Equations ##\mathcal{X}=\frac{\mu^2_BNg^2_j}{3k_BT}J(J+1)=\frac{C}{T}## ##M=\mathcal{X}H## The Attempt at a Solution [/B] ##Fe^{2+}## has a value 4 of J from hunds rules. So I know what the curie factor for iron is ##M=\frac{m}{V}=\frac{HC}{T}##...

Hi all, I've got two questions about the emissions spectrum from solids. Question #1: I feel like I have a reasonable understanding of line absorption and emission spectrum of low density gases based on transitions of electrons between discrete allowed energy levels in a gas. I'm trying to...

I was asked to help with a problem of constructing nets (unfoldings) of Platonic solids. This is supposed to be a high school research project. In my opinion, the problem is not well-defined. There are only five Platonic solids, and their nets are well-known. So I am trying first to come up...

Hi all.. I am currently doing some works on the continuum mechanics. And trying to study the macroscopic behavior of solids ( for simplicity, taken homogeneous materials) upon the action of external force ( which is the stress; pressure). How is it possible to account for the changes that can be...

Say there is a chair soaked in gasoline. If someone is to walk in the room the smell is immediate if the chair was lit on fire the liquid gasoline would ignite the chair. However, what about the particles that constitute the smell of it? Why don't they ignite as well? What is the nature of the...

Homework Statement If the shear stress in steel exceeds about 4.0 x 10^8 N/m^2, the steel ruptures. Determine the shear force necessary to punch a 1-cm diameter hole in a steel plate that is 0.5 cm thick. Homework Equations The Attempt at a Solution The way I tried to solve this problem...

The low temperature heat capacity was experimentally shown to go as T^3 for low temeperatures (and as T for even lower temperatures for metals). This result came out of Debye's model after he modified Einstein's model, relaxing some of his assumptions. I have a few questions on Debye's model...

Why hcl is not an ionic crystal bt Nacl is?? (Both show polarity) https://ssl.gstatic.com/s2/oz/images/cleardot.gif

Hi all, I am forced to step outside of my field to investigate a problem that might root in sublimation of solids. I am trying to calculate the mass (after a certain time) of a material that we know is sublimating at , say .000123 g/(cm^2 hr). Is it as simple as multiplying the rate by the...

For $a>0$, let $V$ be the volume created by revolving the region bounded by $y=b\sqrt{x}$ and $x=a$ around the axis $x=a$. The units of $x$, $y$, and $a$ are $[m]$. The units of $b$ are $[m^{1/2}]$. The value of $b$ remains fixed. For fun and practice, I did this question both with cylindrical...

I encountered a problem where the answer I got was negative. Calculate the volume bounded by $y=x^2-5x+6$, $y=0$, about y-axis. An easy question that is best done with the cylindrical shell method: $$V=2\pi \int_{2}^{3} x(x^2-5x+6)\,dx$$ $$V=\frac{-5\pi}{6}$$ I think I know why it's...

my final is tomorrow and my instructor gave a list of questions that will be similar to the ones on the final exam and i want to see how they should be done properly. I've been working on other problems but i can't get past these ones. thanks determine the volume using the shell method $y=5|x|$...

Homework Statement Consider a solid of compressibility ##\kappa##. Assume that the atoms in this solid are arranged on a regular cubic lattice, the distance between their nearest neighbors being ##a##. Assume further that a restoring force ##-k_0 \Delta a## acts on a given atom when it is...

What are biocompliant solids and what are its use?

Hello Forum! I was wondering: In the rate law expressions, I could never find an example with a solid or a liquid in the reactants in my textbook (Chemistry by Zumdahl). I searched Chemistry (Raymond Chang) and Principles of Molecular Chemistry, without any success. What happens to...

It's known that the concentration of solids don't affect the rate of the reaction since it's concentration is constant, I know that when the number of moles of a solid is increased the volume also increases the same so the concentration remains constant so the rate doesn't change, but when the...

Hi there, first time poster here but I've been following the forum for years - what an outstanding resource! Thanks to all who contribute. Hopefully one day I can add my 2 cents. I have a general question (more of a curiosity) that arose from an observation at work. It has sparked a debate...

Homework Statement Evaluate the definite integral for the surface area generated by revolving the curve about the y-axis: Homework Equations Curve: y=9-x^2 about y-axis The Attempt at a Solution Attached

So I was doing my calc homework when I stumbled upon this thought: lets say you were trying to find the solid of rotation of y=x^2 around the x-axis over the interval [-2,2]. the traditional method would entail pi * integral from -2 to 2 of (x^2)^2 dx while this is easier for a simple...

Homework Statement Consider the infinite region in the first quadrant between the curve y=e^-5x and the x-axis. Find area= 1/5 (got this part) Compute the volume of the solid generated by revolving the region about the x-axis: Compute the volume of the solid generated by revolving the...

Homework Statement Hey, I have problems solving this question. May I know how to solve this question. Somehow, the answer I got is to the power of negative. can someone show me the step by step solution to this question? (Question 18 from this paper) the link is below...

Question I'm really having issues grasping the Volumes of Solids of revolution. I could use some help solving this question, it isn't very hard. 1. Let R be the region bounded by y = x2 and y = x + 2. Find: a) the area of R b) the volume of the solid if R is rotated about the...

I am having issues with solids building up in the 10” discharge ball valves on Mother Liquor Pumps that prevent operations from being able to close the valve. I have had a few discussions regarding ways to improve or eliminate this issue which have included insuring the valve is insulated/traced...

Do intramolecular bonds vibrate in solids...? In case of molecular solids does the Intramolecular bonds(bonds within atoms of a molecule) vibrate as they do vibrate in gas and liquid phases. We are familiar that motion of molecules in solids is in form of vibrations. But when we talk of that...

Do intramolecular bonds vibrate in solids...? In case of molecular solids does the Intramolecular bonds(bonds within atoms of a molecule) vibrate as they do vibrate in gas and liquid phases. We are familiar that motion of molecules in solids is in form of vibrations. But when we talk of that...