What's a difference between mercury and oxygen?
(they both are elements)

--  There are 80 protons in the nucleus of every atom of Mercury,
but only 8 of them in the nucleus of an atom of Oxygen.

-- Mercury must be warmer than 357°C in order to boil, but Oxygen
must only be warmer than -183°C.

--  Mercury must be colder than -39°C in order to freeze, but Oxygen
must be colder than -219°C.

--  Oxygen is required for human life.  Mercury is a deadly poison.

answer and explanation;

composition refers to both the types of minerals within a rock and the overall chemical makeup of the rock while texture refers to the size and arrangement of the minerals or grains that make up a rock. both composition and texture can be used to classify rocks, such as igneous rocks. texture describes how the rock became solid or crystallized from liquid, melted rock. composition of a rock describes the minerals that make up a particular rock.