surface tension and momentum are vectors

Surface tension and momentum are not vectors. Surface tension is a scalar quantity, which is the force acting at the surface of a liquid that causes it to behave as if it were a stretched elastic sheet. It is defined as the force acting at right angles to a line of unit length. It has the units of N/m (Newton per meter).

Momentum, on the other hand, is a vector quantity. It is the product of the mass and velocity of an object. It has both magnitude and direction. The direction of the momentum vector is the same as the direction of the velocity of the object. It has the units of kg.m/s (kilogram meter per second).