I would say compression or the absence of heat because heating a liquid makes it a gas<span />
Answer: (a) There are 0.428 moles present in 12 g of 
molecule.
(b) There are 2 moles present in 
particles of oxygen.
Explanation:
(a). The mass of nitrogen molecule is given as 12 g.
As the molar mass of is 28 g/mol so its number of moles are calculated as follows.
So, there are 0.428 moles present in 12 g of molecule.
(b). According to the mole concept, 1 mole of every substance contains 
atoms.
Therefore, moles present in particles are calculated as follows.
So, there are 2 moles present in particles of oxygen.
Answer:
Three things about our body's systems:
All systems have a method of self-regulation or exogenous regulation by other systems.
All systems have a balance in their functions.
All the systems of our organism are intertwined with each other thus giving general vitality.
Explanation:
Best known systems:
Renal, respiratory, circulatory, cardiac, nervous, immune, blood, muscular systems.
All of them include the participation of one or more organs
Lithium is a good reducing agent because it is electropositive [it rapidly gains electrons]
fluorine is good oxidizing agent electronegative [it loses electrons fastly]
Regard the principle of utilization of two gas.
Make a consistent control of hardware containing gas.
Make a consistent control of weight diminishing valves giving gas.
No smoking zone.
