Which factor is key to the earth having seasons?

the pull of the moon on the earth

how close earth is to the sun

the angle between sunlight and the earth's surface

the speed of rotation of earth on its axis

did you find the answer?

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.