  A linearized polynomial over $\mathbb F_{q^n}$ is called scattered when for
any $t,x\in\mathbb F_{q^n}$, the condition $xf(t)-tf(x)=0$ holds if and only if
$x$ and $t$ are $\mathbb F_q$-linearly dependent. General conditions for
linearized polynomials over $\mathbb F_{q^n}$ to be scattered can be deduced
from the recent results in [4,7,15,19]. Some of them are based on the Dickson
matrix associated with a linearized polynomial. Here a new condition involving
Dickson matrices is stated. This condition is then applied to the
Lunardon-Polverino binomial $x^{q^s}+\delta x^{q^{n-s}}$, allowing to prove
that for any $n$ and $s$, if $\mathbb N_{q^n/q}(\delta)=1$, then the binomial
is not scattered. Also, a necessary and sufficient condition for
$x^{q^s}+bx^{q^{2s}}$ to be scattered is shown which is stated in terms of a
special plane algebraic curve.
