The ground-state electron configuration contains three unpaired 4f electrons.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

c. orbital shape i hope this is correct

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.