Answer:
4.5 moles
Explanation:
One mole is equal to 6.022 x 10^23 atoms
2.71 x 10^24 atoms * 1 mol/ 6.022 x 10^23 atoms = 4.5 moles
 
        
             
        
        
        
Answer:
This stiffening process, called Rigor Mortis, has a roughly known time of occurrence and can therefore be used to estimate time of death. In general: If the body feels warm and no rigor is present, death occurred under 3 hours before. If the body feels warm and stiff, death occurred 3-8 hours earlier.
 
        
             
        
        
        
Answer: A group 1 alkali metal bonded to fluoride, such as LiF. 
Explanation:
Electronegativity is defined as the property of an element to attract a shared pair of electron towards itself. The size of an atom increases as we move down the group because a new shell is added and electron gets added up.
1. A strong acid made of hydrogen and a halogen, such as HCl : A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms. Electronegativity difference = electronegativity of chlorine - electronegativity of hydrogen = 3-2.1= 0.9
2. A group 1 alkali metal bonded to fluoride, such as LiF: Ionic bond is formed when there is complete transfer of electron from a highly electropositive metal to a highly electronegative non metal.
Electronegativity difference = electronegativity of fluorine - electronegativity of lithium= 4-1= 3
3. Carbon bonded to a group 6A (16) nonmetal chalcogen, such as in CO: A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.
Electronegativity difference = electronegativity of oxygen - electronegativity of carbon= 3.5-2.5= 1.0
4. A diatomic gas, such as nitrogen  : Non-polar covalent bond is defined as the bond which is formed when there is no difference of electronegativities between the atoms.
: Non-polar covalent bond is defined as the bond which is formed when there is no difference of electronegativities between the atoms.
Electronegativity difference = 0
Thus the greatest electronegativity difference between the bonded atoms is in LiF.
 
        
             
        
        
        
Answer:
You didn't list the compounds it gave you so i cant cross check them to see it they are ionic bonds( which is  the chemical bonding is formed between metal and nonmetal)
if you reply with the compounds it list I will be happy to check for you
 
        
             
        
        
        
Answer:
The answer to your question is below
Explanation:
                                  ionic compounds                  covalent compounds
1.- Mass                          it does not depend on the type of compound
2.- Conductivity      -conduct electricity               - do not conduct electricity
                                   in solution.
3.- Color                  - Shiny                                     - opaque
4.- Melting point     - high                                       - lower than ionic compounds
5.- Boiling point     - high                                        - lower than ionic compounds
6.- flammability      - not flammable                       - flammable