Number of atoms : 1.26 x 10²³
<h3>Further explanation </h3>
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
0.21 moles of Al, so n = 0.21
Number of atoms :
![\tt N=0.21\times 6.02\times 10^{23}\\\\N=1.26\times 10^{23}](https://tex.z-dn.net/?f=%5Ctt%20N%3D0.21%5Ctimes%206.02%5Ctimes%2010%5E%7B23%7D%5C%5C%5C%5CN%3D1.26%5Ctimes%2010%5E%7B23%7D)
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density 15.4 grams per 1.2³ cm³ ≅ 8.9 grams per cm³
<span>Find the metal that has a density of approximately 8.9 g/cm³</span>
The process by which gasses spontaneously move from an are with higher concentration to one of lower concentration is called diffusion. This process mainly occurs in gases and liquids. The end result of diffusion is called dynamic equilibrium. It is a complete mixing of the molecules of the gas.
Answer:second law of thermodynamics
Explanation:the second law of thermodynamics states that the total entropy of an isolated system can never decrease over time and is constant if only if all processes are reversible.