3) atoms in the same family on the periodic table have
numbers of valence electrons &
properties
a) dissimilar, dissimilar
b) dissimilar, similar
c) similar, similar
d) similar, dissimilar

Atoms  belonging to the same family in the periodic table have Similar numbers of valence electrons & Similar properties .

Explanation:

In a periodic table the atoms are organised depending on the number electrons present in the outer shell. These electrons present in the outer most shell is known as valence electrons. In the periodic table, a atoms having same valence electrons are placed in same group.  

Also the valence electrons plays vital role in determining the properties of the atoms. These properties generally used to predict the chemical reaction. The chemical reaction explains how one element is converted into one or more different elements. Thus elements with same valence electrons has similar properties and undergoes similar chemical reactions.But the strength of those chemical reaction will vary.

your answer is "the 1950's"

compost can be added to topsoil as a:

pesticide