Amajor landmass on earth's surface made of crustal rock is a select one: a. continent b. landform c. formation d. plate

a. continent

Explanation:

The major landmasses on the surface of the Earth made out of crustal rock are called continents. The continents are massive land masses. They lie on top of continental tectonic plates which are less dense and higher than the oceanic tectonic plates. In the present there are six continental masses, all with different shape and size. The continental masses that exist in the present are Eurasia, Africa, North America, South America, Australia, and Antarctica.

h let me think

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-