Answer:
Depends on what are you refering to
Explanation:
So depending on what you are looking for (your question is quite vauge)
there are 5 atoms of the comopound (K2CO3)
within that compound, there are 2 atoms of Potassium and 1 atom of Carbonate. Within Carbonate there are 4 atoms (1 carbon and 3 oxygens)
so answers may be
5, 15, or 25.
I hope this helps.
 
        
             
        
        
        
Answer:
Just click on the answer, if it is an external link DO NOT CLICK IT. it may contain dangerous stuff including h*cked stuff.
Explanation:
 
        
             
        
        
        
The mass of lime that  can  be produced  from  4.510 Kg of limestone  is calculated  as  below
calculate the moles  of CaCO3  used
that is  moles =mass/molar mass
convert  Kg  to g  = 4.510 x1000 =4510g
=  4510 / 100 =45.10 moles
CaCO3 = CaO  +O2
by use of mole ratio between CaCO3  to CaO  (1:1) the  moles of CaO  is also= 45.10 moles
mass of CaO = moles x molar  mass
45.10  x56 = 2525.6  g  of  CaO
        
                    
             
        
        
        
Answer : The final pressure will be, 666.2 mmHg
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.

or,

where,
 = initial pressure = 790 mmHg
 = final pressure = ?
 = initial volume = 101.2 mL
 = final volume = 120 mL
Now put all the given values in the above equation, we get:


Therefore, the final pressure will be, 666.2 mmHg
 
        
             
        
        
        
There is 1 H atom: (1)(+1) = +1 The oxidation number of O is -2. There are 4 O atoms here: (4)(-2) = -8 So the oxidation state of Cl is +7. 
NOTE: The maximum positive oxidation number for chlorine is +7,<span> the same as its group number (VII).</span>