Answer:
The answer to your question is: letter B
Explanation:
Reaction
Cr2O3(s) + 3CCl4(l) ⇒ 2CrCl3(s) + 3COCl2(g)
From the information given and the reaction, we can conclude that:
Green solid = Cr2O3 (s) "s" means solid
Colorless liquid = CCl4 (l) "l" means liquid and is the other reactant
Purple solid = CrCl3(s) CrCl3 is purple and "s" solid
Then, as a green specks remains it means that the excess reactant is Cr2O3, so, CCl4 is the limiting reactant.
Answer:
The average pressure in the container due to these 75 gas molecules is 
Explanation:
Here Pressure in a container is given as

Here
- P is the pressure which is to be calculated
- ρ is the density of the gas which is to be calculated as below

Here
mass is to be calculated for 75 gas phase molecules as

Volume of container is 0.5 lts
So density is given as

is the mean squared velocity which is given as

Here RMS is the Root Mean Square speed given as 605 m/s so

Substituting the values in the equation and solving

So the average pressure in the container due to these 75 gas molecules is 
A nanoparticle is larger than an atom. A nanoparticle is usually made from a few hundred atoms. These particles range from 1 nanometers to 100 nanometers. On the other hand an atom ranges from 0.1 nanometers to 105 nanometers. Using the sizes above, one can clearly see and understand that an atom is smaller.
The two observations you would make about the atoms are
- They are made up largely of empty space
- Their mass is concentrated at the center called a nucleus
These observations were made by Ernest Rutherford in his model of the atom established in 1911, when he performed his gold foil experiment and observed the scattering angle of the alpha particles which led him to conclude that the mass of the atom was concentrated at the center.
Also, that most of the alpha particles also went through the gold foil suggested that the atom was made up basically of empty space.
So,
The two observations you would make about the atoms are
- They are made up largely of empty space
- Their mass is concentrated at the center called a nucleus
Learn more about the atom here:
brainly.com/question/24873449