There are 20 mice in a 5 m2 field ecosystem. The population density of mice is . 20 per m 2
5 per m 2
25 per m 2
4 per m 2

4per m 2

20 mice divided by 5 so it will be 4 per m 2

  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-

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;