Abstract
Let Q
n
be the linear pentagonal-quadrilateral chain containing 2n pentagons and n squares. In this paper, we determined the (normalized) Laplacian spectra of Q
n
based on the decomposition techniques for the corresponding matrices. Further, we obtained explicit expressions for (multiplicative degree-) Kirchhoff index and the number of spanning trees of linear pentagonal-quadrilateral chains which are based on relationships between the coefficients and roots.