a non Noetherian ring that is a Noetherian $\Bbb Z$-module
a Noetherian ring that is a non Noetherian $\Bbb Z$-module
I have no idea in 1, and I'm not sure if $\mathbf{Q}$ is right for 2?
a non Noetherian ring that is a Noetherian $\Bbb Z$-module
a Noetherian ring that is a non Noetherian $\Bbb Z$-module
I have no idea in 1, and I'm not sure if $\mathbf{Q}$ is right for 2?
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Given a ring $R$ that's Noetherian as a $\Bbb Z$-module, it's automatically a (left- or right- as desired) Noetherian ring, as ideals are by definition closed under sum of elements; so every increasing chain of ideals is an increasing chain of $\Bbb Z$-submodules of $R$, and thus stabilizes.
$\Bbb Q$ is indeed a Noetherian ring (it only has two ideals) that's not Noetherian as a $\Bbb Z$-module (consider $(1) \subset (1/2) \subset (1/4) \subset \dots$); we actually know explicitly what the Noetherian $\Bbb Z$-modules are.