  We develop a first-principles theory of resonant impurities in graphene and
show that a broad range of typical realistic impurities leads to the
characteristic sublinear dependence of the conductivity on the carrier
concentration. By means of density functional calculations various organic
groups as well as ad-atoms like H absorbed to graphene are shown to create
midgap states within +-0.03eV around the neutrality point. A low energy
tight-binding description is mapped out. Boltzmann transport theory as well as
a numerically exact Kubo formula approach yield the conductivity of graphene
contaminated with these realistic impurities in accordance with recent
experiments.
