The middle nitrogen has two sigma bonds and one pi bond. You know that one p orbital is used in the double bond and two sp2 orbitals are involved in the sigma bond. This leaves one sp2 orbital for the lone pair to occupy.
Answer: The given statement is true.
Explanation:
According to the Dalton's law, total pressure of a mixture of gases that do not react with each other is equal to the partial pressure exerted by each gas.
The relationship is as follows.

or, 
where,
....... = partial pressure of individual gases present in the mixture
Also, relation between partial pressure and mole fraction is as follows.

where,
= mole fraction
Thus, we can conclude that the statement Dalton's law of partial pressures states that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture, is true.
Answer:
6⅔ shifts
Explanation:
From the question given:
A shift = 4 hours
Pay = $8.25 per hour
Next, we shall determine the number of hours that will result in a pay of $220. This can be obtained as follow:
$8.25 = 1 hour
Therefore,
$220 = $220 × 1 hour / $8.25
$220 = 220/8.25 hours.
$220 = 80/3 hours
$220 = 26⅔ hours
Therefore, it will take 26⅔ hours to receive a pay of $220.
Finally, we shall determine the number of shifts in 26⅔ hours. This can be obtained as follow:
4 hours = 1 shift
Therefore,
26⅔ hours = 26⅔ ÷ 4
26⅔ hours = 80/3 × 1/4
26⅔ hours = 80/12
26⅔ hours = 20/3
26⅔ hours = 6⅔ shifts
Therefore, she will work 6⅔ shifts in order to receive a pay of $220