I believe it would be D. Electromagnet. It's been a while since I've done this stuff, tho. Hope this helps!!!! :)
        
             
        
        
        
<u>Answer:</u> The temperature of the system is 273 K
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
 
  
Given mass of carbon dioxide = 1 lb = 453.6 g   (Conversion factor: 1 lb = 453.6 g)
Molar mass of carbon dioxide = 44 g/mol
Putting values in above equation, we get:

To calculate the temperature of gas, we use the equation given by ideal gas equation:
PV = nRT
where,
P = Pressure of carbon dioxide = 200 psia = 13.6 atm   (Conversion factor:  1 psia = 0.068 atm)
V = Volume of carbon dioxide =  (Conversion factor:
    (Conversion factor:   )
 )
n = number of moles of carbon dioxide = 10.31 mol
R = Gas constant = 
T = temperature of the system = ?
Putting values in above equation, we get:

Hence, the temperature of the system is 273 K
 
        
             
        
        
        
Answer:
4) transferred from the valence shell of one atom to the valence shell of another atom
Explanation:
Electrons are located outside of the nucleus which contains the protons and the neutrons. 
For bonds to form, valence electrons located in the outermost shell electrons are involved. These are the valence electrons. These outer shell electrons can be shared or transferred between two combining atoms to form stable atoms. 
In ionic bonds, the electrons are transferred from one specie to another. The atom that loses the electrons becomes positively charged and the receiving atom becomes negatively charged. This is the crux of ionic bonds. 
 
        
             
        
        
        
It is a poly atomic anion because it has more than one atom and a negative charge
        
                    
             
        
        
        
Answer:
Metal
Element: Calcium
Valency: 2
Explanation:
To find the element, let's use the periodic table. (Look below)
We already went past 3 shells, just need the 2 electrons after it.
Just skip to the 4th row and count 2 to the right
We end up at Calcium.
Calcium is a metal and we're also on the alkaline earth metals column.
Calcium will need to lose 2 electrons to reach stability, so the valency is 2.