Hybridization and bonding in ethenone H2C=C=O?
You are right.the hibrydization is the same with allenes but in allenes there are 2 CH2 groups but in ethenone there is a CH2 and there's a O with two none bonding pairs. The hydrogens will be in the same plane as C=C=O but  the electron pairs on oxygen are not in the same plane