If you melt and cool silicon dioxide under very special conditions
<span>in the laboratory we can grow a single </span>crystalline<span> form of </span>
<span>silicon dioxide that we call quartz. In quartz crystals all of </span>
<span>the molecules are aligned and bonded together in a regular three </span>
<span>dimensional tetrahedral structure forming a very hard, transparent </span>
<span>material with special electronic properties. </span>
1.51 x 10²⁵atoms
Explanation:
Given parameters:
Mass of Na = 578g
Unknown:
Number of atoms = ?
Solution:
To find the number of atoms, we must first find the number of moles the given mass contains.
Number of moles = 
molar mass of Na = 23g
Number of moles =
= 25.13moles
1 mole of a substance = 6.02 x 10²³atoms
25.13 mole of Na = 25.13 x 6.02 x 10²³atoms
This gives 1.51 x 10²⁵atoms of Na
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Avogadro's constant brainly.com/question/2746374
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<span>ability to dissolve ionic substances is the answer</span>
Answer:

Explanation:
Hello,
In this case, for the given chemical reaction, we first identify the limiting reactant by noticing that due to the 1:1 mole ratio for magnesium to iodine the reacting moles must the same, nevertheless, there are only 2.68 moles of magnesium versus 3.56 moles of iodine, for that reason, magnesium is the limiting reactant, so the theoretical turns out:

Thus, we compute the percent yield as:

Best regards.
Answer: Physical change : tearing of paper, fixing of wtaer
Chemical change: rusting of iron , electrolysis of water, Rancidification
Explanation:
Physical change is a change in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance.
Example: tearing of paper, fixing of wtaer
Chemical change is a change in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state.
Example: rusting of iron , electrolysis of water, Rancidification