Air can be separated into its components by means of distillation in special units. So-called air fractionating plants employ a thermal process known as cryogenic rectification to separate the individual components from one another in order to produce high-purity nitrogen, oxygen and argon in liquid and gaseous form.
Answer:
The mass percentage of each element in the compound Al2O3 is 52.9% Al and 47.1% O.
:
Answer:
Only columns
Step-by-step explanation:
The properties of elements vary as you go across a period or down a column.
However, the properties are most similar as you go down a column.
That's because all the elements in a column have the same number of valence electrons.
For example, they may all want to gain one electron, so they will all form the same types of compounds.
The valence electrons determine the chemical properties, so the elements in the same column have the most similar properties.
Answer:
Option B
The atmospheric pressure at sea level is higher.
Explanation:
Atmospheric pressure can simply be understood as the weight of the air molecules in the atmosphere. The higher we go up into the atmosphere, the thinner the air becomes. This means that the air present at higher heights is not so much, and hence, the air is lighter. This is why most fighter jets and mountain climbers need oxygen tanks to breathe properly.
Due to the fact that the air is less dense (lighter) at higher altitudes, it also means that the atmospheric pressure at higher altitudes is less.
Therefore, the atmospheric pressure at the sea level is higher than the atmospheric pressure at altitudes above sea level
