The atomic ratio is a measure of the ratio of atoms of one kind (i) to another kind (j). A closely related concept is the atomic percent (or at.%), which gives the percentage of one kind of atom relative to the total number of atoms.[1] The molecular equivalents of these concepts are the molar fraction, or molar percent.
The given number of moles is a very small fraction of a mole (10 −4 or one-ten thousandth); therefore, we would expect the corresponding mass to be about one-ten thousandth of the molar mass (0.02 g). Performing the calculation, we get.
Atoms[edit]
Solution for Converting.4 in the Fraction is 0.4 = 4 / 10 Below is the Representation of.4 as a Fraction in Graph format. Please Enter Zero Before The Decimal Number Like(0.1,0.34,0.xyz values). Number of molecular orbitals formed from combination of 3s and 3p atomic orbitals in one mole of magnesium atom and fraction of the orbitals that will be occupied by the electrons have to be calculated. Concept introduction: Molecular orbital tells that where an electrons is present in the orbital. For example, if you weigh something on a scale that measures down to the nearest 0.1 g, then you can confidently estimate that there is a ±0.05 g uncertainty in the measurement. This is because a 1.0 g measurement could really be anything from 0.95 g (rounded up) to just under 1.05 g (rounded down).
Mathematically, the atomic percent is https://clucerunun1988.mystrikingly.com/blog/how-to-get-roblox-on-a-school-laptop.
- atomicpercent(i)=NiNtot×100{displaystyle mathrm {atomic percent} (mathrm {i} )={frac {N_{mathrm {i} }}{N_{mathrm {tot} }}}times 100 } %
where Ni are the number of atoms of interest and Ntot are the total number of atoms, while the atomic ratio is
- atomicratio(i:j)=atomicpercent(i):atomicpercent(j).{displaystyle mathrm {atomic ratio} (mathrm {i:j} )=mathrm {atomic percent} (mathrm {i} ):mathrm {atomic percent} (mathrm {j} ) .}
For example, the atomic percent of hydrogen in water (H2O) is at.%H2O = 2/3 x 100 ≈ 66.67%, while the atomic ratio of hydrogen to oxygen is AH:O = 2:1.
Isotopes[edit]
Another application is in radiochemistry, where this may refer to isotopic ratios or isotopic abundances. Mathematically, the isotopic abundance is
- isotopicabundance(i)=NiNtot,{displaystyle mathrm {isotopic abundance} (mathrm {i} )={frac {N_{mathrm {i} }}{N_{mathrm {tot} }}} ,}
Cardhop 1 1 – manage your contacts to my. where Ni are the number of atoms of the isotope of interest and Ntot is the total number of atoms, while the atomic ratio is
- isotopicratio(i:j)=isotopicpercent(i):isotopicpercent(j).{displaystyle mathrm {isotopic ratio} (mathrm {i:j} )=mathrm {isotopic percent} (mathrm {i} ):mathrm {isotopic percent} (mathrm {j} ) .}
For example, the isotopic ratio of deuterium (D) to hydrogen (H) in heavy water is roughly D:H = 1:7000 (corresponding to an isotopic abundance of 0.00014%).
Doping in laser physics[edit]
In laser physics however, the atomic ratio may refer to the doping ratio or the doping fraction.
- For example, theoretically, a 100% doping ratio of Yb:Y3Al5O12 is pure Yb3Al5O12.
- The doping fraction equals,
- NatomsofdopantNatomsofsolutionwhichcanbesubstitutedwiththedopant{displaystyle mathrm {frac {N_{mathrm {atoms of dopant} }}{N_{mathrm {atoms of solution which can be substituted with the dopant} }}} }
See also[edit]
References[edit]
- ^McGraw-Hill Dictionary of Chemistry. McGraw-Hill. 27 January 2003. pp. 31. ISBN0-07-141046-5.
In crystallography, atomic packing factor (APF), packing efficiency, or packing fraction Windows paint mac equivalent. is the fraction of volume in a crystal structure that is occupied by constituent particles. It is a dimensionless quantity and always less than unity. In atomic systems, by convention, the APF is determined by assuming that atoms are rigid spheres. The radius of the spheres is taken to be the maximum value such that the atoms do not overlap. For one-component crystals (those that contain only one type of particle), the packing fraction is represented mathematically by
- APF=NparticleVparticleVunit cell{displaystyle mathrm {APF} ={frac {N_{mathrm {particle} }V_{mathrm {particle} }}{V_{text{unit cell}}}}}
where Nparticle is the number of particles in the unit cell, Vparticle is the volume of each particle, and Vunit cell is the volume occupied by the unit cell. It can be proven mathematically that for one-component structures, the most dense arrangement of atoms has an APF of about 0.74 (see Kepler conjecture), obtained by the close-packed structures. For multiple-component structures (such as with interstitial alloys), the APF can exceed 0.74.
The atomic packing factor of a unit cell is relevant to the study of materials science, where it explains many properties of materials. For example, metals with a high atomic packing factor will have a higher 'workability' (malleability or ductility), similar to how a road is smoother when the stones are closer together, allowing metal atoms to slide past one another more easily.
Single component crystal structures[edit]
Paintsupreme v1 50. Common sphere packings taken on by atomic systems are listed below with their corresponding packing fraction.
- Hexagonal close-packed (HCP): 0.74[1]
- Face-centered cubic (FCC): 0.74[1] (also called cubic close-packed, CCP)
- Body-centered cubic (BCC): 0.68[1]
- Simple cubic: 0.52[1]
- Diamond cubic: 0.34
The majority of metals take on either the HCP, FCC, or BCC structure.[2]
Simple cubic[edit]
For a simple cubic packing, the number of atoms per unit cell is one. The side of the unit cell is of length 2r, where r is the radius of the atom.
- APF=NatomsVatomVunit cell=1⋅43πr3(2r)3=π6≈0.5236{displaystyle {begin{aligned}mathrm {APF} &={frac {N_{mathrm {atoms} }V_{mathrm {atom} }}{V_{text{unit cell}}}}={frac {1cdot {frac {4}{3}}pi r^{3}}{left(2rright)^{3}}}[10pt]&={frac {pi }{6}}approx 0.5236end{aligned}}}
Face-centered cubic[edit]
For a face-centered cubic unit cell, the number of atoms is four. A line can be drawn from the top corner of a cube diagonally to the bottom corner on the same side of the cube, which is equal to 4r. Using geometry, and the side length, a can be related to r as:
- a=2r2.{displaystyle a={2r}{sqrt {2}},.}
Knowing this and the formula for the volume of a sphere, it becomes possible to calculate the APF as follows: Distrust 1 0 download free.
- APF=NatomsVatomVunit cell=4⋅43πr3(22r)3=π26≈0.74048048.{displaystyle {begin{aligned}mathrm {APF} &={frac {N_{mathrm {atoms} }V_{mathrm {atom} }}{V_{text{unit cell}}}}={frac {4cdot {frac {4}{3}}pi r^{3}}{left({2{sqrt {2}}r}right)^{3}}}[10pt]&={frac {pi {sqrt {2}}}{6}}approx 0.740,48048 .end{aligned}}}
Body-centered cubic[edit]
The primitive unit cell for the body-centered cubic crystal structure contains several fractions taken from nine atoms (if the particles in the crystal are atoms): one on each corner of the cube and one atom in the center. Because the volume of each of the eight corner atoms is shared between eight adjacent cells, each BCC cell contains the equivalent volume of two atoms (one central and one on the corner).
Each corner atom touches the center atom. A line that is drawn from one corner of the cube through the center and to the other corner passes through 4r, where r is the radius of an atom. By geometry, the length of the diagonal is a√3. Therefore, the length of each side of the BCC structure can be related to the radius of the atom by
- a=4r3.{displaystyle a={frac {4r}{sqrt {3}}},.}
Atomic 1 0 4 Fraction Calculator
Knowing this and the formula for the volume of a sphere, it becomes possible to calculate the APF as follows:
- APF=NatomsVatomVunit cell=2⋅43πr3(4r3)3=π38≈0.680174762.{displaystyle {begin{aligned}mathrm {APF} &={frac {N_{mathrm {atoms} }V_{mathrm {atom} }}{V_{text{unit cell}}}}={frac {2cdot {frac {4}{3}}pi r^{3}}{left({frac {4r}{sqrt {3}}}right)^{3}}}[10pt]&={frac {pi {sqrt {3}}}{8}}approx 0.680,174,762,.end{aligned}}}
Hexagonal close-packed[edit]
For the hexagonal close-packed structure the derivation is similar. Here the unit cell (equivalent to 3 primitive unit cells) is a hexagonal prism containing six atoms (if the particles in the crystal are atoms). Indeed, three are the atoms in the middle layer (inside the prism); in addition, for the top and bottom layers (on the bases of the prism), the central atom is shared with the adjacent cell, and each of the six atoms at the vertices is shared with other five adjacent cells. So the total number of atoms in the cell is 3 + (1/2)×2 + (1/6)×6×2 = 6. Each atom touches other twelve atoms. Now let a{displaystyle a }be the side length of the base of the prism and c{displaystyle c }be its height. The latter is twice the distance between adjacent layers, i. e., twice the height of the regular tetrahedron whose vertices are occupied by (say) the central atom of the lower layer, two adjacent non-central atoms of the same layer, and one atom of the middle layer 'resting' on the previous three. Obviously, the edge of this tetrahedron is a{displaystyle a }. If a=2r{displaystyle a=2r }, then its height can be easily calculated to be 83a{displaystyle {sqrt {tfrac {8}{3}}}a }, and, therefore, c=423r{displaystyle c=4{sqrt {tfrac {2}{3}}}r } . So the volume of the hcp unit cell turns out to be (3/2)√3a2c{displaystyle a^{2}c } , that is 24√2r3{displaystyle r^{3} } .
It is then possible to calculate the APF as follows:
For the hexagonal close-packed structure the derivation is similar. Here the unit cell (equivalent to 3 primitive unit cells) is a hexagonal prism containing six atoms (if the particles in the crystal are atoms). Indeed, three are the atoms in the middle layer (inside the prism); in addition, for the top and bottom layers (on the bases of the prism), the central atom is shared with the adjacent cell, and each of the six atoms at the vertices is shared with other five adjacent cells. So the total number of atoms in the cell is 3 + (1/2)×2 + (1/6)×6×2 = 6. Each atom touches other twelve atoms. Now let a{displaystyle a }be the side length of the base of the prism and c{displaystyle c }be its height. The latter is twice the distance between adjacent layers, i. e., twice the height of the regular tetrahedron whose vertices are occupied by (say) the central atom of the lower layer, two adjacent non-central atoms of the same layer, and one atom of the middle layer 'resting' on the previous three. Obviously, the edge of this tetrahedron is a{displaystyle a }. If a=2r{displaystyle a=2r }, then its height can be easily calculated to be 83a{displaystyle {sqrt {tfrac {8}{3}}}a }, and, therefore, c=423r{displaystyle c=4{sqrt {tfrac {2}{3}}}r } . So the volume of the hcp unit cell turns out to be (3/2)√3a2c{displaystyle a^{2}c } , that is 24√2r3{displaystyle r^{3} } .
It is then possible to calculate the APF as follows:
- APF=NatomsVatomVunit cell=6⋅43πr3332a2c=6⋅43πr3332(2r)223⋅4r=6⋅43πr333223⋅16r3=π18=π32≈0.74048048.{displaystyle {begin{aligned}mathrm {APF} &={frac {N_{mathrm {atoms} }V_{mathrm {atom} }}{V_{text{unit cell}}}}={frac {6cdot {frac {4}{3}}pi r^{3}}{{frac {3{sqrt {3}}}{2}}a^{2}c}}[10pt]&={frac {6cdot {frac {4}{3}}pi r^{3}}{{frac {3{sqrt {3}}}{2}}(2r)^{2}{sqrt {frac {2}{3}}}cdot 4r}}={frac {6cdot {frac {4}{3}}pi r^{3}}{{frac {3{sqrt {3}}}{2}}{sqrt {frac {2}{3}}}cdot 16r^{3}}}[10pt]&={frac {pi }{sqrt {18}}}={frac {pi }{3{sqrt {2}}}}approx 0.740,480,48,.end{aligned}}}
See also[edit]
References[edit]
Atomic 1 0 4 Fraction Worksheets
- ^ abcdEllis, Arthur B.; et al. (1995). Teaching General Chemistry: A Materials Science Companion (3rd ed.). Washington, DC: American Chemical Society. ISBN084122725X.
- ^Moore, Lesley E.; Smart, Elaine A. (2005). Solid State Chemistry: An Introduction (3rd ed.). Boca Raton, Florida: Taylor & Francis, CRC. p. 8. ISBN0748775161.
Further reading[edit]
- Schaffer; Saxena; Antolovich; Sanders; Warner (1999). The Science and Design of Engineering Materials (2nd ed.). New York, NY: WCB/McGraw-Hill. pp. 81–88. ISBN978-0256247664.
- Callister, W. (2002). Materials Science and Engineering (6th ed.). San Francisco, CA: John Wiley and Sons. pp. 105–114. ISBN978-0471135760.