Answer:
a. Boron trifluoride
b. Propane
c. Dinitrogen pentoxide
d. Carbon Dioxide
e. Silicon Octafluroride?
First, you need to have a periodic table that contains the electronegativities values. once you have them, you just need to subtract the values of the atoms and each bond. I have attached a table with these values. also, it does not matter then order in which you subtract them because they are always positive values. even though you get negative values in your calculator, just make it positive.
H-S----> 2.1 - 2.5= 0.4
H-Cl---> 2.1 -3.0=0.9
H-O---> 2.1- 3.5= 1.4
H-F----> 2.1 - 4.0= 1.9
HF is the most polar because it has the highest electronegativity difference.
Through Air sounds travels approximately 343 meters/second. Why the difference? Because the closer together the molecules in a substance are, the faster sound will travel through that medium.
The statement of letter B, the collisions of particles with one another is completey elastic, is true about Kinetic Molecular Theory. Elastic collisions means that there is no energy transfer between the particles.