Hey there!:
Mass = 21.09 g
Volume = 6.44 mL
Therefore;
Density = mass / Volume
Density = 21.09 / 6.44
Density = 3.274 g/mL

where
the Avogadro's constant that relates the number of particles to their number, in the unit moles
.
The molar mass of propanol- mass per mole propanol- can be directly deduced from its molecular formula with reference to a modern periodic table.

of propanol molecules would thus have a mass of 
“The trapping of the suns warmth in a planets lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planets surface.”
Answer:
See explanation and image attached for details
Explanation:
The reaction involves the heterolytic fission of the Br-Br bond in the bromine molecule to yield a bromine cation which attacks the but-1-ene to form a cyclic intermediate called the brominium ion. The bromine anion must now attack from the opposite face of the brominium ion due to steric clashes to form a product of a 1,2-dibromoalkane having the anti- stereochemistry.
Answer:
A small positively charged nucleus surrounded by revolving negatively charged electrons in fixed orbits