paragraph 1 discusses some differences between pure substances and m
one of the following statements is true? !
a pure substances can be separated by physical changes.
b mixtures can be separated by physical changes.
c the chemical properties of a pure substance are variable
d the physical properties of a mixture never change

B Mixtures can be separated by physical changes.

Explanation:

Mixtures are impure substances with the following features:

Examples of mixture are sea water, muddy water e.t.c

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.

give me abc and i will get it for u.