Answer:
There are 8Si atoms and 16 O atoms per unit cell
Explanation:
From the question we are told that:
Edge length 
Density 
Generally the equation for Volume is mathematically given by



Where
Molar mass of (SiO2) for one formula unit


Therefore
Density of Si per unit length is


Molar mass of (SiO2) for one formula unit


Therefore
There are 8Si atoms and 16 O atoms per unit cell
In order to balance an equation, we apply the principle of conservation of mass, which states that mass can neither be created nor destroyed. Therefore, the mass of an element before and after a reaction remains constant. Here, the balanced equation becomes:
4Al + 3O₂ → 2Al₂O₃
The coefficients are 4, 3 and 2.
Answer:
Mole fraction O₂= 0.43
Explanation:
Mole fraction is the moles of gas/ total moles.
Let's determine the moles of each:
Moles O₂ → 15.1 g / 16 g/mol = 0.94
Moles N₂ → 8.19 g / 14 g/mol = 0.013
Moles H₂ → 2.46 / 2 g/mol = 1.23
Total moles = 2.183
Mole fraction O₂= 0.94 / 2.183 → 0.43
The statement that best describes how an ionic compound dissolves in water is as follows: it separates into individual molecules and is an electrolyte, which is option C.
<h3>What is an ionic compound?</h3>
Ionic compound is any compound is a chemical compound composed of ions (charged atoms) held together by electrostatic forces termed ionic bonding.
Ionic compounds are electrolytes i.e. a substance when, in solution or when molten, ionizes and conducts electricity.
For example; sodium chloride (NaCl) is an ionic compound breaks down into sodium ions (Na+) and chloride ion (Cl-).
Therefore, the statement that best describes how an ionic compound dissolves in water is as follows: it separates into individual molecules and is an electrolyte.
Learn more about ionic compound at: brainly.com/question/9167977
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Explanation:
b. What useful functions do oxidation numbers serve?
It is used to show oxidation and reduction (loss and gain of electrons)
b. How many molecules are in 1 mole of molecules?
1 mole = 6.022 * 10^23 molecules
c. What is the name given to the number of molecules in 1 mole?
Avogadro's Number of molecules
21. a. What is the molar mass of an element?
This is the mass of an element divided by the number of moles.
Molar mass = Mass / Number of moles
b. Write the molar mass rounded to two decimal places of carbon, neon, iron and uranium.
amu = Atomic Mass Unit
Carbon = 12.01 amu
Neon = 20.18 amu
Iron = 55.85 amu
Uranium = 238.03 amu