Answer:
69.7173 u
Explanation:
The abundance of the first isotope is =60.40%
So the abundance of the second isotope =100%-60.40%=39.6%
Atomic mass of first isotope = 68.9257
So the average atomic mass of the first isotope =68.9257×0.6040=41.6311 u
Atomic mass of the second isotope =70.9249 u
So average atomic mass of second isotope =70.9249×0.396=28.086
Now the average atomic mass =41.6311+28.086=69.7173 u
False.
The force of friction is always the direction opposite of the object's movement.
Answer:
B: leaving metal outside in the rain until rust forms an it's surface
Explanation:
Exothermic reaction is defined as the reaction in which release of heat takes place. This also means that in an exothermic reaction, bond energies of reactants is less than the bond energies of products.
Hence, difference between the energies between the reactants and products releases as heat and therefore, enthalpy of the system will decrease.
Whereas in an endothermic reaction, heat is supplied from outside and absorbed by the reactant molecules. Hence, enthalpy of the system increases.
As water acts as a coolent and when fuel rods in a nuclear reactor are immersed in it then heat created by coolent is absorbed by water and then it changes into steam.
Since, absorption of heat occurs in the nuclear reactor. Therefore, it is an endothermic reaction.
Thus, we can conclude that nuclear reactors use fuel rods to heat water and generate steam. This process is endothermic.
I believe Isaac Newtons Law " Gravity ".
