This question involves the concepts of orbital velocity and orbital radius.
The orbital velocity of ISS must be "7660.25 m/s".
The orbital velocity of the ISS can be given by the following formula:

where,
v = orbital velocity = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
M = Mass of Earth = 5.97 x 10²⁴ kg
R = orbital radius = radius of earth + altitude = 63.78 x 10⁵ m + 4.08 x 10⁵ m
R = 67.86 x 10⁵ m
Therefore,

<u>v = 7660.25 m/s</u>
Learn more about orbital velocity here:
brainly.com/question/541239
It is based on atomic number, which is the number of protons in the nuclei of the atoms of an element.
No because they could be different materials for example one could be concrete and one could be aluminium