Help help help awnser 12 and 14
1 answer:
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Answer:
Here's what I get
Explanation:
A plant extract is a mixture because it contains different substances: acetone or ethanol, chlorophylls A and B, carotene and xanthophylls.
It is homogeneous because it is a solution. There is only one phase: the liquid phase. You cannot see the pigments as separate phases.
You can separate the pigments by paper, thin layer, or column chromatography.
Many schools use paper chromatography, because paper is cheap.
As the mixture of pigments follows the solvent up the paper, they separate into different coloured bands according to their attractive forces to the cellulose in the paper.
The chlorophylls are strongly attracted to the paper, so they don't travel very far.
The nonpolar carotene molecules have little attraction to the polar cellulose, so they are carried along by the solvent front.
Answer:
the atomic packing factor of Sn is 0.24
Explanation:
a = b = 5.83A and c = 3.18A.
Volume of unit cell = a²c
= (5.83)² * 3.18 * 10⁻²⁴ cm³
= 1.08 * 10⁻²²cm³
Volume of atoms =
(∴ BCC, effective number of atom is 2)
Volume of atoms =
= 2.55*10⁻²³cm³