<span>The ionic charge of Calcium (Ca) in calcium carbonate (CaCO3) is 2+. CaCO3 has a neutral ionic charge sin CO3 has a 2- charge.</span>
Frenkel defect is a defect in crystalline solids in which an atom is displaced from its lattice position to an interstitial space. This creates a vacant space at the original site and an interstitial defect at the new site within the same element. This defect does not affect the chemical properties of the compound. This defect usually occur in ionic solids with large size difference between the anion and cation.
LiCl does not exhibit Frenkel defect because the size difference between the anion and the cation of the compound is very small.
Answer : A.By
Step by Step Explanation
Answer: There are 
atoms of hydrogen are present in 40g of urea, 
.
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.
According to the mole concept, 1 mole of every substance contains 
atoms.
So, the number of atoms present in 0.67 moles are as follows.
In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.
Thus, we can conclude that there are atoms of hydrogen are present in 40g of urea, .
Explanation:
In order to go from mass of magnesium to atoms of magnesium, we have to do two things:
Convert mass of Mg to moles of Mg using the molar mass of Mg as a conversion factor
Convert moles of Mg to atoms of Mg using Avogadro's number (6.02×1023) as a conversion factor
Step 1:
Before we start, I should note that the molar mass of Mg is 24.31gmol. We can go from mass to moles using dimensional analysis. The key to dimensional analysis is understanding that the units that you don't need any more cancel out, leaving the units that are desired:
48.60g
×1mol24.31g
=2.00mol
Step 2:
We'll use this relationship:
www.sprinklernewz.uswww.sprinklernewz.us
Using the moles of Mg that we just obtained, we can use Avogrado's number to perform dimensional analysis in order to cancel out units of mol to end up with atoms of Mg:
2.00mol
×6.02×1023atoms1mol
=1.204×1024atoms
Thus, 48.60g of Mg is equivalent to 1.204×1024atoms
Hope this helped :)
