The elements from this section of the periodic table all belong to the same A. Family
B. Group
C. Period
D. Valence
Plz help!!

C. Period

Explanation:

The elements from this section of the periodic table belongs to the same period.

A period on the periodic table is a horizontal arrangement of elements according to their atomic number.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.