Answer:
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. ... For instance, all the group 18 elements are inert gases.
Explanation:
Answer:
The specific shape that an electron moves in inside a sub-level <em><u>shell</u></em><em><u>.</u></em>
The answer is astronomy. There is no ÓLOGY´ at the end of it.
Helium was first discovered in space before it was on earth
