Answer: 
Explanation:
Geometrical symmetry of the molecule and the polarity of the bonds determine the polarity of the molecule.
The molecule that has zero dipole moment that means it is a geometrically symmetric molecule and the molecule which has some net dipole moment means it is a geometrically asymmetric molecule.
As the molecule is symmetric, the dipole moment will be zero as dipole moments cancel each other and the molecule will be non-polar.
As the molecule is asymmetric, the dipole moment will not be zero and the molecule will be polar.
Example: 
Thus, we can say that
is a polar molecule.
Answer:
Isotopes of an element are atoms of the same element that have different number of neutrons.
Answer:
True
Explanation:
The entropy of a system denoted by S is a thermodynamic function that increases in value when there are more ways to arrange the particles in the system. Some spontaneous chemical processes are entropy driven. An increase in entropy is said to drive the dissolution of ionic salts along with the evaporation of water are related to the spreading out of energy.
The entropy of a system can be taken as a measure of disorder of a system. In a spontaneous chemical process, the entropy of the universe is said to increase. ΔSunivu>0. Making the answer true.
Answer:
a- The paper towel with more thermal energy
Explanation:
The paper towel with a higher temperature is one with more thermal energy.
Temperature is the degree of hotness or coldness of a body. And it is a measure of the average kinetic energy of the particles within a medium or body.
As body gains more thermal energy which is a form of kinetic energy, the average kinetic energy of its particles increases.
This will in turn lead to an increase in the temperature of the substance.
So, the paper towel with more thermal energy will have a higher temperature.
Answer:
When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number 2 less than the starting atom.
Explanation:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number 2 less than the starting atom.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy