Element Definition and 836 Threads

how would you set this up to solve this problem A newly discovered element occurs naturally as the two isotopes: 108X and 114X. In nature 65.8 % of is the isotope 108X and the remaining percentage is 114X. What is the mass number for element X.

Is there a quick way to define a vector with 100 elements going between two different values? I know of just using division and using that as a step size, but it would be nice if there was something quicker.

Homework Statement Determine the wt% of lithium required to obtain an Al-Li alloy with a density of 2.55 g/cm^3. Homework Equations The Attempt at a Solution I am so lost in this problem, any hints of how to start this problem with GREATLY appreciated!

In atomic decay, when an atom decays and releases the (Alpha) Helium nucleus, the atom left behind changes to the element 2 Proton Numbers prior. So is this new element charged? because the electrons stay behind, or do they go? and if so, where to and how?

Homework Statement I'm asked to say whether the set Q,+,. is a field. To be a field it must respect 8 conditions. And one of them is that there exists a unique element -x in Q such that x+(-x)=0 for all x in Q. I realize I have to prove the existence of -x but also its uniqueness. For the...

Find the Finite element solution for a equation: (∂^2 u)/〖∂x〗^(2 ) +(∂^2 u)/〖∂y〗^2 +λu-c=0 using linear triangular finite elememts. In the above equation u is scalar,λ is a constant and is a body force term(constant). The boundary conditons are in terms of prescribed values of the function...

I am to design a sensor element that can detect a leakage through a thin metal disc (rupture disc) in a pipeline. Ideally, the metal disc closes the pipeline at the upstreaming side with certain pressure. Its downstream can be either open to atmosphere or close. When a higher pressure occurs...

Help! I trying to improve momentum eq for cylindrical element coordinate by using vector method or may other methods Please give me response v.ergent . Thanks! =)

I need some help understanding a definition: This is supposed to be an explanation of what the author did on the page before. He had just described how to construct a (complex) Hilbert space from a (real) smooth manifold with a smooth nowhere vanishing volume element, and then moved on to...

What is the percent CdSO4 by mass in a 1.0 molal aqueous solution? My attempt: CdSO4 is 208.47g/mol 1.0 molal = 1 mol CdSO4/1kgH2O Converted mols to grams, and kg to g. 208.47g Cd/1000g H2O = .20847 .20847 x 100 to get % mass = 20.8% It is an old test question that I am going over...

prove or disprove n sigma notation 2i-1 = 2n, for all n is an element of N. i=1 N = natural numbers

Homework Statement Aluminium-Lithium alloys have been developed by the aircraft industry to reduce the weight and improve the performance of its aircraft. A commercial aircraft skin material having a density of 2.47 g/cm3 is desired. Compute the concentration of Li (in wt%) that is required...

Given two definite positive definite matrices A and B of identical size with the following relationship of their diagonal elements: A_{ii} \geq B_{ii} (no summation) which also holds after any unitary change of coordinates \textbf{A}'=\textbf{U}^T\textbf{A}\textbf{U} where...

This seems like it should be easy, but my combinatorics is (are?) a little rusty. I want to know how many permutations of a given length leave at least one element unchanged, and how many leave exactly one unchanged. Started wondering about it when picking names out of a hat for a secret...

If a is the only element of order 2 in a group, does it belong to the centre Z(G)?

I'm currently studying factor groups in abstract algebra and needed some help understanding how to determine the order of an element in a factor group Suppose I have Z (mod 12) / <4>. And I choose some random element from Z (mod 12) such as 5 or 7. How would I go about determining the order...

Homework Statement Which of the elements, from the second period, has the highest density in its standard state? Homework Equations Standard state is gas at 1 atm, concentration of 1 M for liquid, or pure substance at 25C and 1 atm. The Attempt at a Solution I thought that N, O, F...

I am a new to ANSYS command-language mode. I am having trouble animating the procedure described below. The procedure is meant to model melting over time through element death (based on example from U. Alberta at www.mece.uAlberta.ca/tutorials/ansys/AT/BirthDeath/BirthDeath.html). My...

Homework Statement x = \frac{u^{2} + v^{2}}{2} y = uv z = z Find the arc length given: u(t) = cos(t), v(t) = sin(t), z = \frac{2t^{\frac{3}{2}}}{3} Homework Equations ds^{2} = dx^{2} + dy^{2} + dz^{2} In curvilinear coordinates thhis becomes ds =...

Homework Statement element X reacts with oxygen to produce a pure sample of X2O3 . in an experiment, it is found that 1.0g of X produces 1.1596g of X2O3 . what is the molar mass of X? Homework Equations The Attempt at a Solution well we can write a equation for it 4X + 3O2 --->...

I was wondering if we can use magnets to spin items in a way that they will continuously spin for a very long time with good conditions of the material used. By this I mean it can spin for a very long time without being touched or relying on any other thing to help it spin. other then the pull...

Find a set A (subset of R,set of real numbers) and an element a of R such that there is no bijecton from a+A(we add a to the set A)to A. I can't find a good example. Can someone help Are we done if we choose the empty set? (And is the empty set a subset of R?) Thank you

Homework Statement Let G be a group such that every x in G\{e} has order 2. (a) Let H<=G be a subgroup. Show that for every x in G the subset H U (xH) is also a subgroup. (b) Show that if G is finite, then |G|=2^n for some integer n. The Attempt at a Solution For (a), I know that since...

Homework Statement In S_3, show that there are four elements satisfying x^2=e and three elements satisfying y^3=e. The Attempt at a Solution I don't understand what the question is asking at all...

Homework Statement The natural abundaces of elements in the human body, expressed as a percent by mass, are oxygen (o) 65%; carbon (C), 18%; hydrogen (H), 10%; nitrogen (N), 3.0%; calcium (Ca), 1.6%; phosphorous(P), 1.2%; all other elements 1.2% Calculate the mass in gram of each element in...

I would like some help in calculating the basic Friedman equations starting from the flat FRW universe line element, Once I have calculated the Christoffel symbols for this metric how do i get to the Friedman equation, any link to a good book will be really helpful, thanks, seetesh.

The element rubidium consists of two isotopes; the stable Rb-85 and the radioactive Rb-87 (abundance 27.83%). What is the specific activity of natural rubidium chloride? if you use A(r)=85.47 g.mol-1 for Rb-element, A(r)= 86.91 g.mol-1 for Rb-87, and M(r) = 120.92 g.mol-1 for RbCl.

I'm looking at project investigating thermal dissiplation around circular and square concrete piles, resting in a homogeneous material (soil) using two-dimensional finite element analysis. I'm applying a transient thermal loading cycle to the centre of the concrete pile over a 7-day test...

I noticed somewhere the line element of a two-dimensional torus is written in the form ds^2=r^2(d\theta^2_1+d\theta^2_2) The author only states that he assumes same radius parameter for simplicity and no further explanation is given. But I do not understand how that form is possible. I...

i need a full explanation on finite element method or better still a material i can read to help me understand better

[SOLVED] Differential Area Element While doing surface integrals, I am not sure as to which of the following is the correct differential area element to be considered: i] dA = dx dy or ii] A = xy hence, using the product rule: dA = xdy + ydx

Homework Statement Element X forms a chloride, XCln which melts at 3\circC. When 0.500 g of the chloride reacts with an excess of acidified silver nitrate, 1.19g of AgCl are formed. Another 0.500g sample of the chloride is heated strongly and chlorine gas is given off. When the residue is...

Hey there Could anybody answer the following question on dust grains and depletion of Silicon and Carbon on dust: If D(Si)=-3, D(C)=-0.5, and the logarithmic cosmic abundances of Silicon and carbon relative to H as 12 are 7.5 and 8.5 respectively, what is the ratio of the number of atoms of...

The hunt for superheavy elements has focused banging various heavy nuclei together and hoping they’ll stick. In this way, physicists have extended the periodic table by manufacturing elements 111, 112, 114, 116 and 118, albeit for vanishingly small instants. Although none of these elements is...

Hello, am a bit confused when to use beam element and when to use Finite element? is the beam element a subset of Finite element?

I've read Schwarzschild paper and I don't understand his conditions "The solution is spatially symmetric with respect to the origin of the co-ordinate system in the sense that one finds again the same solution when x,y,z are subjected to an orthogonal transformation(rotation)" Could...

Hi all, I have to write a small program that reads the results from a finite element analysis and calculates some results in arbitrary points. The results could be either nodal or element based. What would be the best approach to do this? I've thought about using the shape functions to...

Homework Statement An element of atomic number 82 and mass number 214 decays radioactively to an element of atomic number 82 and mass number 210. Which of the following emissions achieve this result? Check all that apply. a. four beta particles b. two beta particles and one alpha...

Can anyone tell me what book is best to learn MATHEMATICS that used in Finite Element Analysis (FEA) algebraically and analytically?

Hello folks :) I need to model a finite element model of a beam in bending in matlab i need directions and help thanks

This summer i have an internship that expects me to write a program to analyze this inflatable vacuum chamber. The advisor wants to be able to put in a geometry and see if it will be stable. Would finite element analysis programs be able to do this? If so which one should I look into getting?

I am attempting to model a simple 2D surface in ANSYS that is subjected to a load in the 3rd dimension. My surface is a table top, in the X-Y plane. I have modeled it in 2D, and will give it a "simulated thickness". However, I am not sure which element type I can use to apply a force on the top...

As part of the exploration of one of the moons of Jupiter, a probe digs under the surface, where it finds a pocket of gas. It starts to do some on-board experimentation. The data stored in the probe's computer include the following table of Mulliken electronegativity values of gases. Element...

Organic element symbol "R" I keep hearing different things about what exactly the letter R represents in organic chemical structures. Does the R always represent an alkyl group or can it represent groups with heteroatoms? For example...

Homework Statement How many subsets of a set with 100 elements have more than one element? The thing throwing me off here is the zero-set, and whether it counts as an element or that. Can someone start me off?

[SOLVED] Is 0 a prime? Am I missing something or is 0 a prime element in an integral domain? In the definition of prime element p of an integral domain, we only ask that the ideal generated by p, be prime. Well (0) is obviously prime because if ab=0 in an integral domain, then it is that...

If the Ricci-scalar R is constant for a given spatial hypersurface, then the curvature of that region should be homogenous and isotropic, right? A homogenous and isotropic hypersurface (disregarding time) has by definition the following line element (due to spherical symmetry): d\sigma^2 =...

I need to heat styrene to its forming temp of around 325 degrees F. I have a heating gun that operates at too many amps to use safely at home. So I found these temp controllers that don't use a lot of energy, but can get hotter then my blow dryer can, yet not as hot as the 700 degree heat gun I...

Hey folks, Does anyone know how to get the line element on a torus? The ds^2 term. I want to find the metric for toroidal geometry. Any help appreciated! Richard

Is wondering if anyone knows if the modulus square of the double matrix element that arises in Wigner-Eckart theorem obeys the same "rule" as the ordinary does, if the operator is hermitian: |<ajm|M|bj'm'>|^2 = |<bj'm'|M|ajm>|^2 if M is hermitian. Is then : |<aj||M||bj'>|^2 =...