Answer:
option a and c both are correct 
Explanation:
please mark me as brainliest 
 
        
             
        
        
        
When the volume is 450 cm3 so the boat will displace 450 g.
so we have  450 g - 14.5g = 435.5 left 
so to get how many pennies can be added to the boat before it sinks can be determined by:
divided the mass for the one penny:
no.of Penny = 435.5 / 2.5g
                     = 174.2 
∴ the boat will float with 174 pennies and will start to sink with 175 
        
             
        
        
        
Matematically speaking, maybe because:
The number of substances = number of elements + number of different combinations of those elements
        
             
        
        
        
Answer:
 the periodic table is important because it is organized to provide a alot of information about elements and how they relate to one another in one easy-to-use reference. The table can be used to predict the properties of elements, even those that have not yet been discovered.
Explanation:
 
        
             
        
        
        
Answer : One mole of an ideal gas  occupies a volume of 22.4  liters at STP.
Explanation :
As we know that 1 mole of substance occupies 22.4 liter volume of gas at STP conditions.
STP stands for standard temperature and pressure condition.
At STP, pressure is 1 atm and temperature is 273 K.
By using STP conditions, we get the volume of 22.47 liter.
Hnece, the one mole of an ideal gas  occupies a volume of 22.4  liters at STP.