First off, you must realize that the phase changes are marked by the points B and D on the graph. They are level because all of the energy (or heat) being added is being consumed by the physical process. So The temperature is increasing before the phase change, and after the phase change. The moments before and after are represented by points A, C, and E.
Explanation:
Elements heavier than Helium are synthesized in a number of environments. For elements that are lighter than Iron, those elements are synthesized during various phases in the evolution of massive stars. For elements heavier than Iron, one needs quite a bit of energy input to form these heavy elements.
Answer:
The surface is most likely to be made of Sodium.
Explanation:
Firstly, we determine the threshold wavelength and the work function of the metal by using Einstein's Photoelectric Equation.
Einstein's Photoelectric Equation:
= threshold wavelength
= wavelength = 190 nm = 
K.E. = the kinetic energy of the emitted electrons = 4.0 eV = 
By substituting the above numbers in the equation, the threshold wavelength of the metal can be found:
= 
= 490.2 nm
The work function = 
= 
= 2.534 eV
The metal with which the surface of the table is made can be determined by the work function.
The above work function is most close to that of Sodium which has a work function of 2.38 eV
Therefore, the surface of the table is most likely to be made of Sodium.
<h3><u>Answer;</u></h3>
A bond is formed, and the reaction is exothermic.
<h3><u>Explanation;</u></h3>
- An endothermic reaction takes more energy to break the bonds of the reactants than is released when the bonds of the products are formed.
- <em><u>Chemical bond formation is always an exothermic process and chemical bond breaking is an endothermic process. When bonds are formed the system loses energy and hence increases its stability.</u></em>
- In this case; Cl + Cl —> Cl2 + 58 kcal ; bond between two Cl atoms are being formed and thus the reaction is exothermic as it releases energy to the surrounding.
Answer:
the us and the soviet union
Explanation:
