The relative atomic mass of an element is the mass of its atoms compared with that of which element?

left to right the atomic number increases by 29.

Explanation: for example

Choose two elements to compare. __K and __V

What are their atomic numbers? 39 and __50

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.