I think the correct answer is the first option. It has nonpolar bonds and a symmetrical structure. The structure of a BF3 molecule shows a symmetrical trigonal geometry. The net dipole moment of the molecule is zero therefore it is polar.
Explanation:
To convert moles to particles or grams to particles, let us have a firm understanding of what a mole is.
A mole is the unit of measuring quantity of particles.
It is the amount of substance that contains the Avogadro's number of particles.
The particle can be atoms, molecules, formula units, electrons, protons, neutrons, etc.
So, to convert from moles to particles;
1 mole of a substance contains 6.02 x 10²³ particles
To convert from grams to particles;
First convert to moles;
number of moles =
So, 1 mole of a substance contains 6.02 x 10²³ particles
C is correct. Have a good day!
The answer is Three
!!!!!!
Answer:

Explanation:
Hello,
In this case, the enthalpy of combustion is understood as the energy released when one mole of fuel, in this case octene, is burned in the presence of oxygen and is computed with the enthalpies of formation of the fuel, carbon dioxide and water as shown below (oxygen is circumvented as it is a pure element):

Thus, since we already know the enthalpy of combustion of the fuel, for carbon and water we have -393.5 and -241.8 kJ/mol respectively, thereby, the enthalpy of combustion turns out:

Best regards.