The term sublimation is used to describe the conversion of a solid directly to a gas, without passing through the liquid state. This process is an endothermic process which means that it needs a supply of energy to happen. It happens at a temperature and pressure that is below the triple point of a substance. There are some substances that prefers sublimation rather than evaporation like arsenic and carbon. This is for the reason that the pressure for the triple point of these substances are very high and it would be difficult for them to be at the liquid state. The energy needed for sublimation to happen is calculated from the sum of enthalpy of vaporization and enthalpy of fusion.
The answer will be b. membrane.
The most abundant element in the Sun and in the stars are hydrogen and helium. Like most of the stars, there is a spontaneous radioactive reaction happening in the Sun. Hydrogen is transformed into Helium. As long as the stars are young, the most abundant element is hydrogen.
The answer is theory because it says if and that means theory
Answer:
CCl4
Explanation:
Let us look at the structure of CCl4 closely in order to really determine if it is the correct answer to the question or not.
While it is true that the electro negativity of carbon is 2.5 and that of chlorine is 3.0, hence an electro negativity difference of 0.5 exists between carbon and chlorine leading to the presence of four polar covalent bonds in the carbon tetrachloride molecule. We must also observe that the molecule, carbon tetrachloride, has a tetrahedral molecular geometry. This implies that the four dipoles in the molecule are symmetrical and cancel out each other hence the molecule is non polar. Being a non polar molecule, only London forces are expected to be present as an intermolecular force, hence the answer.
