2mgo à 2mg + o2 is an example of a chemical reaction.
a. synthesis
b. combustion
c. replacement
d. decomposition

2MgO → 2Mg + O2 is an example of a decomposition chemical reaction. The answer is letter D. It is not a replacement reaction because no other compound is involved. It is not a combustion reaction because no oxygen is involved.

D. decomposition

Explanation:

Synthesis reaction occurs when two elements or compounds react to originate a new one:

A + B ⇒ C  

Combustion occurs when a fuel reacts with oxygen to form CO₂ and water:

A + O₂ ⇒ CO₂ + H₂O

Replacement reaction can be simple or double. Simple occurs when a simple element replaces others in a compound:

A + BC ⇒ B + AC

Double occurs when two compounds replace elements between them:

AB + CD ⇒ AC + BD

Decomposition reaction occurs when a compound originates two or more compounds

A ⇒ B + C

So, the reaction given is a decomposition chemical reaction.

here is table 2-2:

country

percent of eligible voters that voted

rank

united states

44.9%

138

canada

60.1%

107

costa rica

84.6%

14

hungary

66.9%

82

japan

57.0%

118

egypt

27.7%

159

south africa

85.5%

10

ans is no, the data set cannot be plotted as a single circle graph

level 4 to level 2 : ))