Final answer:
The nuclear decay where oxygen decays to form nitrogen and emits an electron is called beta decay, which involves the transformation of a neutron to a proton in the nucleus.
Step-by-step explanation:
The type of nuclear decay where oxygen decays to form nitrogen, accompanied by the emission of an electron, is known as beta decay. In beta decay, a neutron in an unstable nucleus is transformed into a proton, and this process involves the ejection of an electron (often represented by the Greek letter beta, β) and sometimes a neutrino. The transformation of nitrogen-16 to oxygen-17 is an example of beta decay, where the mass number remains constant, but the atomic number increases by one.