Potential energy relative to the surface is
(mass) x (<span>acceleration due to gravity) x (height above the surface).
At 1.0 meter above the surface, that is
</span> (mass) x (<span>acceleration due to gravity) x (1.0 meter) .
The object's mass doesn't change, so the only thing that has any effect
on its potential energy at 1 meter above the surface is the acceleration
of gravity or, in other words, the surface of <em><u>what</u></em> ?
</span>
Hello!
These atoms are isotopes
Isotopes are atoms with the same number of protons (which determine the atomic number) and a different number of neutrons. These two atoms have the same number of protons (13), but a different number of neutrons, so they are isotopes.
According to their number of protons, these are Aluminum isotopes: ²⁷Al (stable), and ²⁶Al (radioactive), respectively.
Have a nice day!