Which of the following pairs of elements belong to the same group?
a.(h)& (he)
b.(li)& (be)
c.(c)& (pb)
d.(ga)& (ge)

Carbon and Lead make the most sense

Explanation:

None of them are in the same group but carbon and lead are in the same column. Hydrogen is an other non-metal and Helium is a noble gas, Lithium is an Alkali metal and Beryllium is an Alkaline earth metal, Carbon is an other non-metal and Lead is a Post-transition metal, Gallium is Post-transition metal and Germanium is a Metalloid. So none of the pairs are in the same group, but carbon and lead do share the same column.

particle   p is an electron and particle q is a neutron

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.