Explanation:
Atomic size gradually decreases from left to right across the periodic table because within a period of elements, all electrons are added to the same shell. However, at the same time, protons are being added to the nucleus, making it more positively charged. The effect of increasing proton number is greater than that of the increasing electron number. Therefore, there is a stronger nuclear attraction. This means that the nucleus attracts the electrons more strongly, pulling the atom's electron shells closer to the nucleus. As a result, the atomic diameter of the atom decreases. 
 
        
             
        
        
        
The Sea and the ocean are just different terms that mean same thing
 
        
                    
             
        
        
        
Answer:
The change in enthalpy is +210 kJ, so it is an endothermic reaction.
Explanation:
- The change in enthalpy shows that the reaction is exothermic or endothermic.
 
The change in enthalpy = The energy of products - the energy of reactants.
- If ΔH is positive value, the reaction is endothermic, the energy of the products is higher than that of the reactants.
 
- If ΔH is negative value, the reaction is exothermic, the energy of the products is lower than that of the reactants.
 
<em>For this reaction: </em>The change in enthalpy = The energy of products - the energy of reactants = 370 kJ - 160 kJ = + 210 kJ.
<em>So, the right choice is: The change in enthalpy is +210 kJ, so it is an endothermic reaction.</em>
 
        
                    
             
        
        
        
Answer:
Explanation:
mass of the reactant = mass of the product 
15.31 + 1.50 = 16.81g
 
        
             
        
        
        
Answer:
C
Explanation:
Check it. So u can know it