A and C are incorrect because they are not complete transfer of valence electrons. Ionic bonds best to form a neutral molecule
Answer: 
Explanation:
Firstly we need to know that 
, then we cam make the conversion:
This is the height of Mount Everest in feet
However, we can express it using scientific notation by counting to the left the decimal spaces:
Explanation:
Combustion of a compound is the reaction with oxygen , hence , the process of combustion is an oxidation reaction.
The carbohydrates contain more amount of oxygen as compared to the fats ,
Hence ,
carbohydrates , have a lot of oxygen contents , are are already partially oxidized , but fats have lower oxygen content .
Therefore ,
The partially oxidized carbohydrates are very difficult to oxidized in comparison to fats .
Answer: Carbon dioxide is a pure substance.
Explanation: A pure substance is defined when a substance has a single type of molecule. If more than 1 type of molecule is present in a substance, then it is considered as a mixture.
- Soda is basically a mixture of water and carbon dioxide. More than 1 type of molecule is present.
- Gasoline is a mixture of may gases. More than 1 type of molecule is present.
- Salt water contains salt and water molecules, hence it is considered as a mixture.
- Carbon dioxide has only 1 type of molecule which is
molecules. Hence, it is a pure substance.
The chemical equation without coefficients is:
Ca + CO2 + O2 --------> Ca CO3
You can balance that equation by trial an error.
This is the chemical equation balanced:
2Ca + 2CO2 + O2 --------> 2Ca CO3
Count the atoms on each side to check the balance
Atom Left side right side
Ca 2 2
C 2 2
O 2*2 + 2 = 6 2*3 = 6
Then those are the coefficients:
a0 = 2
a1 = 2
a2 = 1
a3 = 2
