A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide, mica ( which is quartz, or SiO 2 ) , and iodine. The results of her investigations are: (a) W is a good electrical conductor; X, Y, and Z are poor electrical conductors. (b) When the solids are hit with a hammer. W flattens out. X shatters into many pieces. Y is smashed into a powder, and Z is not affected. (c) When the solids are heated with a Bunsen burner. Y melts with some sublimation, but X, W, and Z do not melt. (d) In treatment with 6 M HNO 3 , X dissolves; there is no effect on W, Y, or Z. On the basis of these test results, identify the solids.
A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide, mica ( which is quartz, or SiO 2 ) , and iodine. The results of her investigations are: (a) W is a good electrical conductor; X, Y, and Z are poor electrical conductors. (b) When the solids are hit with a hammer. W flattens out. X shatters into many pieces. Y is smashed into a powder, and Z is not affected. (c) When the solids are heated with a Bunsen burner. Y melts with some sublimation, but X, W, and Z do not melt. (d) In treatment with 6 M HNO 3 , X dissolves; there is no effect on W, Y, or Z. On the basis of these test results, identify the solids.
Solution Summary: The author explains that ionic crystals are made up of ions that are bonded by the electrostaticforce of attraction.
A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide, mica
(
which is quartz, or SiO
2
)
,
and iodine. The results of her investigations are: (a) W is a good electrical conductor; X, Y, and Z are poor electrical conductors. (b) When the solids are hit with a hammer. W flattens out. X shatters into many pieces. Y is smashed into a powder, and Z is not affected. (c) When the solids are heated with a Bunsen burner. Y melts with some sublimation, but X, W, and Z do not melt. (d) In treatment with 6 M
HNO
3
,
X dissolves; there is no effect on W, Y, or Z. On the basis of these test results, identify the solids.
A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide (PbS), quartz which is SiO2,
and iodine. The results of her investigations are: (a) W is a good electrical conductor; X, Y, and Z are poor electrical conductors. (b) When the solids are hit with a hammer, W flattens out, X shatters into many pieces, Y is smashed into a powder, and Z is not affected. (c) When the solids are heated with a Bunsen burner, Y melts with some sublimation, but X, W, and Z do not melt. (d) In treatment with 6 M HNO3, X dissolves; there is no effect on W, Y, or Z. On the basis of these test results, which samples are; Au, PbS, SiO2, and I2
A metal X has an atomic radius of 0.126 nm. If the density and molar
mass of X are 7.87 g cm3 and 55.85 g mol1, respectively.
1.
(a)
(i)
Determine the number of atoms per unit cell and the crystal
structure of metal X.
(ii)
Determine the volume of the unit cell.
(ii)
Determine its planar density in [100], [110] and [111] directions.
(iv)
Explain which direction would be the most possible slip direction
when shear stress is applied.
(b)
Explain the role of matrix and reinforcement phase in a composite
material.
(b) Using the Crystallographer's
formula to determine the density (in g/cm³) of Po:
ρ = Σ Ζ * Μ
Vell* N
You must know that a primitive cubic cell has Z = 1
Since Po is a metal, the value of "i" = 1, since it's the only entity!
MM of Po= 208.998 g/mol
Vcell (in cm³) = a³
Vcell (3.36 x 10-8 cm)³ = 3.793 x 10-23 cm³
N = 6.022 x 1023 atoms/mol
Thus: p = (1 atom/cell) (208.998 g/mol) = 9.16 g/cm³
(3.793 x 10-23 cm³) (6.022 x 1023)
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Unit Cell Chemistry Simple Cubic, Body Centered Cubic, Face Centered Cubic Crystal Lattice Structu; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=HCWwRh5CXYU;License: Standard YouTube License, CC-BY