It’s B the cu looses its 2 and passes it to the NH3 that needs a bracket to separate them. The NH3 doesn’t loose its 3 because it’s already a compound!
Hope this helps!
This problem is honestly, very easy. Just grab a periodic table and find the element in Group 1 and Period 7. But first, let's discuss how the elements are arranged systematically in a periodic table. There are a lot of scientists who contributed to it, but the most famous one is Dimitri Mendeleev. He arranged the elements according to their atomic number. The elements starts from 1 which is Hydrogen up to the heaviest known elements which is Oganesson with an atomic number of 118. As you can observe, there is a gap between groups 3 and 4. This is done so that the periodic table does not take too much space horizontally. Thus, they are just placed at the bottom. These elements are called lanthanides (upper row) and actinides (lower row). The rows in the periodic table are called groups, and the columns are called periods.
Now, the element at the lower left corner (Group 1, Period 7) is Francium, abbreviated as Fr. It has an atomic number of 87. Some elements are actually synthesized, but Francium is a naturally occurring radioactive element. It was discovered by Marguerite Perey in France.
It is B, smoke and air pollution can stress the lungs and cause things like Respiratory distress if not wearing a proper mask. That is why in places with massive amounts of air pollution many people will wear face masks.
Answer: 252.5 kPa
Explanation:
Given that:
initial volume of gas V1 = 5.00 L
initial pressure of gas P1 = 101 kPa.
new Volume V2 = 2.00 L
new pressure P2 = ?
Since, only pressure and volume are involved, apply the formula for Boyle's law
P1V1 = P2V2
101 kPa x 5.0L = P2 x 2.00L
505 = P2 x 2.00L
P2 = 505/2.00
P2 = 252.5 kPa
Thus, the new pressure of gas inside the piston is 252.5 kPa