Answer:

Explanation:
The formula for the heat released is
q = mCΔT
Data:
  m = 395 g
  C = 4.184 J·°C⁻¹g⁻¹
ΔT = 55 °C
Calculations:
q = 395 × 4.184 × 55 = 91 000 J = 91 kJ
The water will absorb 
 of energy.
 
        
             
        
        
        
Answer: 0.462 moles
Explanation: 13C indicates an isotope of carbon and its mass number is 13. It means the mass of 1 mol of 13C is 13 gram. 
The question asks to calculate the number of atoms present in 6.00 grams of 13C. 
To calculate the number of moles we divide the given grams by the mass of 1 mol of the element. The set could be shown easily using dimensional analysis as:

= 0.462 moles
So, there will be 0.462 moles of atoms in 6.00 grams of 13C. 
 
        
                    
             
        
        
        
Answer:
Pu-239
Explanation:
Beta decay moves the element which undergoes the decay one place to the right in the periodic table since to conserve charge and being beta radiations an  electron we convert a neutron into a proton and an electron. In neutron capture we increase the atomic mas by one unit. We that in mind, lets solve the question:
U-238 + ₁⁰ n ⇒ U-239 ⇒ Np -239 +  ₋₁⁰β ⇒ Pu-239 +  ₋₁⁰β
 
        
             
        
        
        
The property that determines an atom;s ability to attract electrons shared in a chemical bond is electronegativity. The correct answer is C.