What is meant by soil? How is soil formed?

Fill in the blanks with the appropriate term. 
(Temperature, volume, mass, density, humidity, acidic, weight, neutral, shape.) 
The capacity of air to hold moisture depends upon the _____ of the air.

Fill in the blank with the appropriate term.

(volume, mass, density, humidity, acidic, weight, neutral, shape)

While freezing, the _____ of water is lowered.

Fill in the blanks with the appropriate term.
(Temperature, volume, mass, density, humidity, acidic, weight, neutral, shape)
_____ soil has pH 7.