2H2O=2H2+O2
37.4g H2O(1 mol/18.02)=2.07547 mol H2O
PV=nRT
(1.30)(V)=(2.07547)(.0821)(297)
Vwater=38.92898L
38.92898L (1 mol O2/2 mol H2O)=19.46449L O2 gas
The correct statement is " A single bond, because they overlap orbitals to share one pair of electrons." A fluorine atom is unstable with 7 electrons in its valence shell and so needs one more electron to achieve stability. This is according to the octet rule which states that an atom will gain or lose electrons until there are 8 electrons in its valence shell. So each fluorine donates an electron to form a single pair and the 
achieves a noble gas configuration.
Atmosphere. You can think of the atmosphere as the outer shell for earth.
Lecithin is an emulsifier agent that's composed of 5 smaller molecules: phosphoric acid, choline, glycerol( is the backbone), and two fatty acids.
The fatty acids, which are hydrophobic (afraid of water), makes this substance more similiar to fats and represent the non-polar part of the lecithin.
The phosphate group is the polar portion of the molecule and it's the negatively charged. The choline is positively charged, which readily dissolve in water<span>.
</span><span>Lecithin is a good emulsifier because of these structural features. the hydrophobic contacts with the oil, while the hydrophilic end contacts with the water.</span>
