Answer:
b
Explanation:
because it be an the only answer there
DNA
Nucleoulos
Nuclear Membrane
Answer: The activation energy is 10 kJ and the reaction is exothermic.
Explanation: Exothermic reactions are those in which heat is released and thus the energy of products is less than the energy of reactants.
Endothermic reactions are those in which heat is absorbed and thus the energy of products is more than the energy of reactants.
Activation energy is the extra amount of energy required by the reactants to cross the energy barrier to convert to products.
Given : Energy of reactants = 40kJ
Energy of activation: (50-40)=10 kJ
Energy of products = 50 kJ
Energy of products = 15 kJ
Thus Energy of products (15kJ) < Energy of reactants(40kJ), the reaction is exothermic as energy has been lost to surroundings in the form of heat.
Explanation:
When a large block of ice is placed in a hot cup of water then some of the ice will melt into the cup. As a result, when ice melts then after sometime temperature of cup will become equal to the temperature of ice.
Therefore, ice won't melt further as surface area of cup is small so, only some of the ice will melt into it.
Whereas when same block melts when dropped into a lake it completely melts because lake has large surface area and hence, ice will melt into it easily. This is also because there is different in temperature of both ice and lake.
So, ice will melt into it as temperature of ice will be less than the temperature of lake.
