The outermost energy shell of an atom
because they are involved in forming bonds
What is the mole ratio of  to Fe? if oxygen it is 4:3 Fe3O4
Heat energy because the energy in seismic waves that causes the ground to shake is heat energy. Heat energy associated with friction on the fault slip surface
Please mark me as braunliest
The answer is C. Hydrogen Bond
Alkaline Earth Metals are the elements located in the second period from the left of the periodic table. These elements lose two electrons to form the stable octet when forming an ionic bond, resulting in a net charge of +2. Because they’re trying to get rid of those electrons to get to the stable octet, it’s easy to remove them - this means that the ionization energy of these elements is relatively low. Finally, since they’re looking to get rid of electrons, they certainly aren’t trying to gain any, meaning that their electronegativity is relatively low.
The correct answers are A and D.