Answer:
I believe you are asking about the objective lens or eyepiece.
Explanation:
Objective lenses are used to magnify objects enough for you to see them in great detail
Eyepiece/Ocular is what you look through at the top of the microscope.
A tube connects the eyepiece lens to objective lenses, which enhance the magnification power of the eyepiece lens. Both the eyepiece and the objective lens contribute to the magnification of the object.
The eyepiece lens usually magnifies 10x, and a typical objective lens magnifies 40x.
Answer:
0.299 moles of PCl5
Explanation:
First form an equation based of given information: P4 + Cl2= 4PCl5
Next balance it: P4 + 10Cl2 = 4PCl5
Take your given value (53.0g of Cl2) and divide it by its molar mass to get moles of Cl2: 53.0g/70.906g = 0.747 moles Cl2
Then, multiply by the molar ratio (10Cl2 to 4PCl5): (0.747 x 4 mol PCl5)/10 mol Cl2 = 0.299 moles PCl5
Answer:
The ionization energy (in kJ/mol) of the helium ion is 21,004.73 kJ/mol .
Explanation:

Z = atomic mass
n = principal quantum number
Energy of the electron in n=1,

Energy of the electron in n = ∞

Ionization energy of the
ion:


To convert in into kj/mol multiply it with 
