Thursday

April 17, 2014

April 17, 2014

Number of results: 79

**chemistry**

Is the calculation of percentage of each atom within a Body centered cubic cell AKA volume of the BCC cell same as the atomic packing factor for the BCC unit cell. The BCC % is 68%. the atomic packing factor is just 0.68. Am I completely wrong? And also how do i calculate the ...
*Wednesday, January 13, 2010 at 11:58pm by Anonymous*

**Statistics**

Could someone help out with this question. The answer is 1842, but i'd like to know how to solve it. Thanks BCC wants to estimate the proportion of its students who are single parents. How many students should BCC survey if it wants to be 99% confident that the sample ...
*Friday, October 28, 2011 at 10:47am by Jay Ortwein*

**chemistry**

What is the plane and lattice structure that is represented in this picture? SC (100) BCC (100) FCC (100) SC (110) BCC (110) FCC (110) SC (111) BCC (111) FCC (111)
*Friday, April 26, 2013 at 6:25pm by Maikol*

**chemistry**

No. The bcc is 68% and the factor is, of course, 0.68. Fe is a bcc, also, and if you know r, then 4r = a(3)2 and you can calculate a. Here is a site that gives a,b,c and much more information about iron. a, b, and c are about 286 something pm. The volume would, of course, be ...
*Wednesday, January 13, 2010 at 11:58pm by DrBob222*

**Chemistry**

Find the unit cell (simple, bcc, fcc), type of holes where the smaller ions are found (tetrahedral, octrahedral, cubic), and number of cations and anions per unit cell for the following compounds: CdSe CsI Li2O KBr NaCl ZnS(I) i did this and i got most of my answers wrong!!! ...
*Monday, February 15, 2010 at 4:43am by kooler*

**Chemistry**

For molibdenium We see from the PT that Mo is a BCC material, so the face diagonal [011] has 2⋅(12) atoms over a distance of 2√a. The value of the lattice parameter a can be found in the same manner as the previous problem (noting that the BCC structure has only 2 ...
*Friday, November 15, 2013 at 3:21pm by DDD*

**Chemistry**

Body centered cubic lattices (bcc) and simple cubic lattices are not close packed; therfore, the spheres touch on the sides and top and bottom but one layer doesn't fit into the holes of another layer as the close packed layers do. So AAAA would be the way to describe the ...
*Tuesday, February 12, 2008 at 2:08am by DrBob222*

**chemistry**

What do you have available? You can get at this two or three ways. Do you know the side, a, for them? Then volume of unit cell = a3 for both BCC and FCC. For volume of atoms, look up the formula for volume of a sphere. I think it's (4/3)*pi*r3. For BCC, multiply that by 2 ...
*Thursday, February 11, 2010 at 1:37am by DrBo222*

**Difracction problem**

a. BCC
*Sunday, June 2, 2013 at 6:43am by himani.*

**AP Chemistry**

bcc means 2 atoms per unit cell. mass of unit cell is 2*55.847/6.022 x 10^23 = ?? g/unit cell. mass = volume x density or volume = mass/density = ??g/7.86 g/cc = xx cc a (the edge length) = volume1/3 for a bcc crystal, radius = (a/4)*31/2. Check my thinking. I obtained 2.87 x ...
*Saturday, November 14, 2009 at 11:50am by DrBob222*

**bcc**

I'm anxiously awaiting the rest of your post.
*Friday, February 26, 2010 at 9:30pm by DrBob222*

**Gen Chem**

edge=4r/sqrt3 in bcc
*Monday, April 19, 2010 at 9:59am by bobpursley*

**bcc**

what are the changes to n02 levels in one day
*Wednesday, September 15, 2010 at 2:07am by luke*

**solid chemestry**

a. BCC b. 3.17 I don't have c yet!
*Friday, November 15, 2013 at 11:45am by koala*

**Chemistry**

An element has bcc packing with a body-centered cubic unit cell. Its density is 19300 kg/m3 and the unit cell volume is 3.17 x 10-26 L. Calculate the molar mass (g/mol) of the element to three significant figures. The element rubidium has bcc packing with a body-centered cubic...
*Monday, February 8, 2010 at 9:47pm by Dan*

**bcc**

how do you work equation dealing friction and newtons when pulling the distance of a block
*Friday, February 26, 2010 at 9:28pm by jack*

**Physics**

Sodium has bcc packing. If a distance between two nearest atoms is 3.7 A* then what is the lattice parameter?
*Thursday, April 19, 2012 at 2:36pm by Tulika*

**bcc**

t=9 h = t + b/3 b = h+t knowing t=9, we have h = 9 + b/3 b = h+9 so, h = 9 + (h+9)/3 h = 9 + h/3 + 3 2h/3 = 12 h = 18 b = 27 t = 9 add 'em up for the total weight
*Thursday, February 20, 2014 at 7:15pm by Steve*

**chemistry**

I tried but its graded wrong 4 times. thats correct it is BCC. atom of this area is ! only but still tere is a mistake
*Friday, April 26, 2013 at 1:29am by anonyms*

**chemistry**

yo what were your type of holes for this problem?? the type of packing for bcc is A-B-A
*Monday, February 18, 2008 at 9:02pm by poopoopoo*

**chemistry**

Nb is BCC and if you solve it, it gives you 2667 Volts but when you put it as your answer it gives X mark :(
*Saturday, December 21, 2013 at 5:46am by Anonymous*

**chemistry**

Lithium is a BCC Crystal a = 3.5092 * 10^-8 Planar Density (001) (top plane) = 1/a^2 = 8.12 * 10^14
*Friday, April 26, 2013 at 1:29am by Karl*

**Science/math**

BCC crystal structure, atomic radius of .1363, and an atomic weight of 95.94g/mol. How would you compute the theoretical density?
*Tuesday, September 15, 2009 at 1:16pm by Z32*

**AP chem**

I have a problem set due tomorrow, and two problems in it were not covered in class. The first is this: Molybdenum has an atomic radius of 0.145 nm. The volume of its cubic unit cell is 0.0375 nm^3. What is the geometry of the molybdenum unit cell? I have no idea where to even...
*Thursday, December 7, 2006 at 6:04pm by chris*

**math**

an element has a BCC structure with cell edge of 288pm. the density of the element is 7.2g/cm3. how many atom are present in 208g of the element?
*Tuesday, January 1, 2013 at 8:52am by ahamad sultan*

**Chemistry**

a=2.77 Å= 2.77•10⁻⁸ cm. The BCC-cell volume is V=a³=(2.77•10⁻⁸)³ = 2.13•10⁻²³ cm³. Density ρ =8.65g/cm³ per unit cell. Avogadro´s number N₀=6.022•10²³ mol⁻¹. The number of ...
*Thursday, January 17, 2013 at 3:26pm by Elena*

**college chem**

Fe is a bcc. mass unit cell = 2*atomic mass Fe/6.02E23 = ?
*Monday, February 4, 2013 at 11:02pm by DrBob222*

**chemistry**

Determine the radius of the largest atom that can be accommodated in the interstices of BCC iron (Fe) without stress. (Hint: the center of the largest site is at ½, ¼, 0; draw a unit cell - it helps.)
*Wednesday, April 3, 2013 at 8:08pm by adex*

**chemistry**

Determine the radius of the largest atom that can be accommodated in the interstices of BCC iron (Fe) without stress. (Hint: the center of the largest site is at ½, ¼, 0; draw a unit cell - it helps.)
*Thursday, April 4, 2013 at 8:14am by adex*

**chemistry**

The element K has bcc packing with a body-centered cubic unit cell. The density of K is 0.862 g/mL. Calculate the volume (L) of the unit cell of K.
*Saturday, February 21, 2009 at 6:05pm by tweety*

**bcc = ???**

If you really want an expert to help you, be sure to follow directions and type your subject in the School Subject box. Any other words, including obscure abbreviations, are likely to delay responses from a teacher who knows that subject well.
*Wednesday, November 23, 2011 at 8:41pm by Writeacher*

**chemistry**

If lithium is a BCC crystal. planar density is atoms per area the 001 plane look like this o--o | | o--o the sides are equal to lattice constant a and the atoms in this area = 4(1/4) = 1
*Friday, April 26, 2013 at 1:29am by Karl*

**bcc**

if you put honey,water,dishwashing liquid and vegetable oil in a clear jar and then you add asmall of plastic cup, plastic fork, straw and a small piece of styrofoam cup.
*Friday, February 26, 2010 at 9:30pm by jack*

**Biomaterials**

What is the theoretical density of tantalum (Ta) with the following characteristics: Crystal structure: BCC Atomic radius: 14.6 Angstroms Atomic weight: 180.9 g/mol density needs to be in g/cm^3
*Tuesday, May 22, 2012 at 10:23pm by Nate*

**chemistry**

Determine the radius of the largest atom that can be accommodated in the interstices of BCC iron (Fe) without stress. (Hint: the center of the largest site is at ½, ¼, 0; draw a unit cell - it helps.) Radius (in centimeters):
*Tuesday, April 2, 2013 at 11:41pm by adex*

**chemistry**

The element lithium has bcc packing with a body-centered cubic unit cell. The volume of the unit cell is 4.32 x 10-26 L. Calculate the density (g/cm3) of the element.
*Saturday, February 21, 2009 at 6:03pm by tweety*

**Chemistry**

The element niobium has bcc packing with a body-centered cubic unit cell. The volume of the unit cell is 3.59 x 10-26 L. Calculate the density (g/cm3) of the element
*Wednesday, May 12, 2010 at 3:17pm by Anon*

**chemistry**

how do i calculate the volume of a unit cell and volume of atoms within a unit cell for FCC and BCC
*Thursday, February 11, 2010 at 1:37am by blasting*

**bcc**

One canned juice drink is 30% orange juice, another is 10% orange juice. How many liters of each should be mixed together in order to get 20L that is 18% orange juice?
*Wednesday, November 23, 2011 at 8:41pm by ms*

**Math Alg2**

The number of computers sold by BCC depends on the dollar amount, x, that they spend on advertising. How many computers will they sell by spending $100,000 on advertising? Round to the nearest whole number and do not include units in your answer.
*Thursday, April 12, 2012 at 11:17am by Moonshadow*

**algebra**

The number of computers sold by BCC depends on the dollar amound,x, that they spend on advertising. How much must they spend to sell 200 computers? Round to the nearest dollar and do not include units in your answer. N(x)=100+20 * In(0.25x)
*Wednesday, June 29, 2011 at 3:07pm by Katie*

**chemistry**

Find the unit cell (simple, bcc, fcc), type of holes where the smaller ions are found (tetrahedral, octrahedral, cubic), and number of cations and anions per unit cell for the following compounds: CdSe CsI Li2O KBr NaCl ZnS(I)
*Tuesday, February 12, 2008 at 10:35pm by jina*

**chemistry**

The element Rb has bcc packing with a body-centered cubic unit cell. The density of Rb is 1.532 g/cm3 and the cell volume is 1.852 x 10-22 mL. Calculate the value of Avogadro's number to three significant figures based on these data.
*Saturday, February 21, 2009 at 6:05pm by tweety*

**Math- Alg 2**

The number of computers sold by BCC depends on the dollar amount, x, that they spend on advertising. How many computers will they sell by spending $80,000 on advertising? Round to the nearest whole number and do not include units in your answer. N(x) = 100 + 20 * In(0.25x)
*Thursday, January 26, 2012 at 11:41pm by CAMILA*

**Science**

This must refer to some lab experiemnt of data obtasined from an experiment. I have no idea what radiation was used, and what you mean by the "second peak." You also don't explain what "two theta" means in terms of the experiment. The lattice paramenter can be obtained from ...
*Wednesday, August 15, 2012 at 12:21am by drwls*

**Boolean Algebra**

use it twice (bc'+a'd)(ab'+cd') = bc'(ab'+cd') + a'd(ab'+cd') = abb'c' + bcc'd' + aa'b'd + a'cdd' Now, since xx' = 0, the result is 0
*Saturday, February 9, 2013 at 1:00pm by Steve*

**math**

what is the number of each atom in the unit cell of a BCC cystalline structure unit cell. I know its 2 atoms=8/8 +1 Calculate what % of each atom is contained within the unit cell? How do I do this
*Wednesday, January 13, 2010 at 10:46pm by Anonymous*

**Difracction problem**

i think b only ask for the expression, not the actual value????...beside, in order to get the actual value of lattice constant, we need the radius...is the radius given or can it be determined???... i tried expressing the lattice constant for the BCC as 4r/sqrt3 but can't get ...
*Sunday, June 2, 2013 at 6:43am by bonjo*

**chemistry**

There are two Li atoms per unit cell for a bcc structure. mass = 2*massofmole Li/6.022 x 10^23 = mass of unit cell. You know the volume. density = mass/volume.
*Saturday, February 21, 2009 at 6:03pm by DrBob222*

**Probability**

I get 33.333% The each unit of energy has 3 possible landing. So the total possibilities are 3*3*3 = 27. There are 3 ways in which B has one unit and is the first unit. (BAA, BAC, BCC). So, there must also be 3 ways where B gets the second unit and 3 ways where B gets the ...
*Monday, October 22, 2007 at 10:58pm by economyst*

**chemistry**

I don't know why it is wrong. But I'm sure about the answer. The atoms you need broke on (100) plane are the four in the plane bonded to the body central atom (remember that each atom in a BCC Crystal has 8 neighbors but you only need broke 4 - if you broke the 8 bonds you ...
*Friday, May 31, 2013 at 8:17am by DrB*

**Chemistry**

Marcia I don't know why it is wrong. But I'm sure about the answer. The atoms you need broke on (100) plane are the four in the plane bonded to the body central atom (remember that each atom in a BCC Crystal has 8 neighbors but you only need broke 4 - if you broke the 8 bonds ...
*Friday, January 11, 2013 at 10:27am by DrB*

**bcc**

the tail weighed 9 pounds. the hyead weighed as much as the tail plus 1/3 of the body combined, and the body weighed as much as the head and tail combined. what was the total weight of the fish?
*Thursday, February 20, 2014 at 7:15pm by handel*

**chemistry**

My solution if BCC first plane to give maximum wavelenth is (110) plane. Then use lambda = 2dsin(theta) but since you want to maximize the lamdba assume that (theta) = 90 degrees So lambda = 2d only d = a(lattice constant) / sqrt (h^2 + k+2 + l^2) solve for a, plug in (110) ...
*Saturday, December 21, 2013 at 5:46am by Anonymous*

**chemistry**

I tried to find a good site for you to read but failed. The statement the problem makes is confusing. While it may be true that the V atoms occupy only the lattice POINTS, it also is true that if it is body centered there must b an atom at the center. There are 8 corner V ...
*Thursday, January 20, 2011 at 9:58pm by DrBob222*

**Chemistry**

Remember these. A bcc unit cell has 2 atoms/unit cell. A fcc unit cell has 4 atoms/unit cell. A simple cubic unit cell has 1 atom/unit cell.
*Monday, February 8, 2010 at 9:47pm by DrBob222*

**bcc**

You might find some detail here http://www.epa.gov/airtrends/nitrogen.html However NO2 levels (note the capital N) vary from location to location.
*Wednesday, September 15, 2010 at 2:07am by Dr Russ*

**Difracction problem**

Diffraction from an unknown cubic metal is observed to occur at the following values of θ when using CuKα radiation. Determine the crystal structure to find the lattice constant. 20.1⁰, 29.2⁰, 36.6⁰, 43.5⁰, 50.2⁰, 57.4⁰, 65.5&#...
*Sunday, June 2, 2013 at 6:43am by Eys*

**Science/math**

My best guess is that this is 136.3 pm which converts to 136.3 x 10^-9 m or 1.363 x 10^-8 cm. Then d (the diagonal in the bcc) is 4r = 4 x 1.353 x 10^-8 = 4.452 x 10^-8 cm and d^2 = 3a^2. Solve for a and I get 3.148 x 10^-8 cm and volume is a^3 = ?? mass of unit cell is 2 ...
*Tuesday, September 15, 2009 at 1:16pm by DrBob222*

**AP Chemistry**

bcc is 2 atoms/unit cell. mass unit cell = 2*55.847/6.02E23 = ? volume unit cell = mass unit cell/density a = edge length = volume1/3 4r = a*(3)1/2 and solve for r = approximately 1.2E-8 cm. volume of atom = (4/3)*pi*r3 ratio is space used = (2*volume of atom/volume of unit ...
*Tuesday, November 27, 2012 at 8:40pm by DrBob222*

**Chemistry**

Calculate the radius of a vanadium atom, given that V has a BCC crystal structure, a density of 5.96 g/cm3, and an atomic weight of 50.9 g/mol. I used this equation: density = (2)*(atomic weight) / (volume of unit cell)*(Avagodro's #) rearranged to find the volume of the unit ...
*Wednesday, January 16, 2013 at 3:14am by Kyle*

**Chemistry**

Calculate the radius of a vanadium atom, given that V has a BCC crystal structure, a density of 5.96 g/cm3, and an atomic weight of 50.9 g/mol. I used this equation: density = (2)*(atomic weight) / (volume of unit cell)*(Avagodro's #) rearranged to find the volume of the unit ...
*Wednesday, January 16, 2013 at 8:49pm by Kyle*

**Chemistry**

The bcc has two atoms/unit cell. The edge is 3.5 x 10^-8 cm = a Volume = a3 = 3.5 x 10^-8)^3 cc mass = volume x density mass = a3 x 7.49 g/cc = xx 2atoms/unit cell x atomic mass/6.022 x 10^23 = xx mass Solve for atomic mass.
*Monday, May 3, 2010 at 7:37pm by DrBob222*

**math**

This is math?? Yes, there are two atoms/unit cell in a bcc. I don't know how much information you have but the general idea is to calculate the volume of the unit cell (vol = mass/density), then calculate the volume of the two atoms [(4/3)*pi*r^3 for each of the two atoms]. ...
*Wednesday, January 13, 2010 at 10:46pm by DrBob222*

**Chemistry**

1- 7.36e-2 189 2-metal Solid hydrogen has a half filled s-band insulator Solid helium has a filled s-band 3-1.13 semiconductor 4-Ionization of phosphorus requires some minimum temperature n_type The concentration of conduction electrons is fixed by the concetration of ...
*Friday, November 15, 2013 at 2:28pm by Anon*

**bcc**

oj in x liters of 30% = .3x oj in (20-x) liters of 10% = .1(20-x) oj in 20 liters of 18% = .18(20) .3x + .1(20-x) = .18(20) .3x + 2 - .1x = 3.6 .2x = 1.6 x = 8 so, 8L of 30% + 12L of 10% = 20L of 18% 8*.3 + 12*.1 = 2.4+1.2 = 3.6 = .18*20
*Wednesday, November 23, 2011 at 8:41pm by Steve*

**calculus**

If you look for some list of identities for vector products, such as wolfram: cross product you will find the following: A.(BxC) = det(ABC) (AxB)x(CxD) = det(ABD)C - det(ABC)D If we adapt this formula to our problem, we need to set A = b B = c C = c D = a Now, we plug and chug...
*Wednesday, September 14, 2011 at 12:53pm by Steve*

**Chemistry**

The enthalpy of atomization of nobium is 745 KJ/mole. The energy per atom is = 745000/Avogadro Number = 1.2371305e-18 J/atom In a BCC structure each atom has 8 neighbors. Then The energy per bond is = 1.2371305e-18 / 8 = 1.5464132e-19 J/bond Now in a (100) plane the atoms ...
*Friday, January 11, 2013 at 10:27am by DrB*

**chemistry**

The enthalpy of atomization of nobium is 745 KJ/mole. The energy per atom is = 745000/Avogadro Number = 1.2371305e-18 J/atom In a BCC structure each atom has 8 neighbors. Then The energy per bond is = 1.2371305e-18 / 8 = 1.5464132e-19 J/bond Now in a (100) plane the atoms ...
*Saturday, June 1, 2013 at 8:13am by DrB*

**chemistry**

The enthalpy of atomization of nobium is 745 KJ/mole. The energy per atom is = 745000/Avogadro Number = 1.2371305e-18 J/atom In a BCC structure each atom has 8 neighbors. Then The energy per bond is = 1.2371305e-18 / 8 = 1.5464132e-19 J/bond Now in a (100) plane the atoms ...
*Friday, May 31, 2013 at 8:17am by DrB*

**chem**

The enthalpy of atomization of nobium is 745 KJ/mole. The energy per atom is = 745000/Avogadro Number = 1.2371305e-18 J/atom In a BCC structure each atom has 8 neighbors. Then The energy per bond is = 1.2371305e-18 / 8 = 1.5464132e-19 J/bond Now in a (100) plane the atoms ...
*Friday, January 11, 2013 at 11:28am by DrB*

**chemistry**

The enthalpy of atomization of nobium is 745 KJ/mole. The energy per atom is = 745000/Avogadro Number = 1.2371305e-18 J/atom In a BCC structure each atom has 8 neighbors. Then The energy per bond is = 1.2371305e-18 / 8 = 1.5464132e-19 J/bond Now in a (100) plane the atoms ...
*Sunday, June 2, 2013 at 11:29am by DrB*

**chemistry**

I think the answers probably are that the edge lengths are the same; i.e., a = b = c and all the angles are the same. The angles are 90 degrees in all cases. The way I read the question, however, it seems to ask what is true for ALL three of the cubic lattices. And the answer ...
*Tuesday, February 12, 2008 at 2:34am by DrBob222*

**chemistry**

This problem is from my chemistry book and I am having a little trouble with the intermediary steps: Barium metal crystallizes in a body- centered cubic lattice (atoms at lattice points only) The unit cell edge length is 502 pm, and the density of the metal if 3.5g/cm^3. (...
*Tuesday, May 18, 2010 at 3:59pm by Tokey*

**Chemistry**

(a) The phase diagram of the binary system, neodymium-scandium ( Nd-Sc ) is given below. There are two polymorphs in the solid state: alpha which is hexagonal close packed (HCP) and beta which is body-centered cubic (BCC). Identify all phases present at points 1, 2, and 3. ...
*Tuesday, December 11, 2012 at 3:35am by Odesa*

**chemistry**

(a) The phase diagram of the binary system, neodymium-scandium (Nd-Sc) is given below. There are two polymorphs in the solid state: α which is hexagonal close packed (HCP) and β which is body-centered cubic (BCC). Identify all phases present at points 1, 2, and 3. ...
*Monday, December 17, 2012 at 6:02am by anita*

**chemistry**

First Consider the Lattice Type of Potassium , and that is BBC Then determine where the 110 "plane" is Now, if you can imagine the (110) position you can see that cutting the unit cell at that position will rapture two K-K bonds. Hence to know that surface energy you need to ...
*Saturday, December 21, 2013 at 10:08am by JavaLovesC#*

**Chemistry**

1- Which of these processes will lower the glass transition temperature of a glass? Increase the cooling rate Decrease the cooling rate Increase amount of network modifier Decrease amount of network modifier Quench the glass to cool the surfaces quickly Decrease the number of ...
*Tuesday, October 29, 2013 at 5:42pm by youlifex*

**Chemistry**

1- Which of these processes will lower the glass transition temperature of a glass? Increase the cooling rate Decrease the cooling rate Increase amount of network modifier Decrease amount of network modifier Quench the glass to cool the surfaces quickly Decrease the number of ...
*Wednesday, October 30, 2013 at 9:07am by youlifex*

Pages: **1**