Newton's second law of motion can be formally stated as follows:
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
This verbal statement can be expressed in equation form as follows:
a = Fnet / m
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:
It means the chemical entity is a radical
Explanation:
When we talk of unsaturation, we are referring to the number of pi-bonds in a chemical entity. The alkane, alkene and alkyne organic family are used to as common examples to explain the term unsaturation.
While alkynes have 3 bonds, it must be understood that they have 2 pi bonds only and as such their degree of saturation is two.
In the case of an alkene, there is only one single pi bond and as such the degree of unsaturation is 1.
Now in this case, we have a fractional 0.5 degree of unsaturation alongside the 3 to make a total of 3.5. So what’s the issue here?
The fractional part shows that the chemical entity we are dealing with here is a radical. While the integer 3 shows that there are 3 pi-bonds, the half pi bond remaining tells us that there is a missing electron on one of the atoms involved in the chemical bonding and as such, the 1/2 extra degree of unsaturation tends to tell us this.
Kindly recall that a radical is a chemical entity within which we have at the least an unpaired electron.
