Answer:
The resulting nuclide will be polonium-214.
Step-by-step explanation:
Alpha decay: It is a process in which alpha particles is emitted when a heavier nucleus decays into lighter nuclei. The alpha particle released has a charge of +2 units.
The general alpha decay reaction is given as:

Beta-decay: It is a process in which a neutron gets converted into a proton and an electron releasing as a beta-particle. The beta particle released carries a charge of -1 units.

Atom of polonium-218 after alpha decay and two emissions:
1)

2)

3)

The resulting nuclide will be polonium-214.