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 

Answer:
there are four peaks in the 13c NMR (B)
Answer:
ionic compounds are made from metal and non mental elements
Explanation:
in this case it is know as an ionic compound because it contains a charge. For example, NaCl is simply a compound as it contains no charges (the charges cancel out as Cl is -1 and Na is +1)
but OH- is an ionic compound as it has a charge if -1 (O has a -2 charge and H has a +1 charge, so -2+1=-1 so OH has -1 charge)
Answer:
Mg2 + O2 → 2MgO
Explanation:
Hope this helps!! I got it right.
The density of a pure gold is 19.32g/cm3
if the volume is 4.30 cm3 then we can calculate the mass using the formula mass=density x volume
mass=19.32*4.30
mass=83.076g