In this activity, you’ll watch a video of an experiment that relates to climate change. The experiment compares the effects of heat on carbon dioxide and air. Watch the video now. Then answer the series of questions below. Part A In the video, the experimenter used a model to represent a phenomenon observed in the natural world. What did the light and each of the flasks represent in this model?

  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-

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

b) nuclear ive learned that in a pedtrodic table