Wherever the scientists put the magnet or electric force on the glass tube, the ray bent in that direction. The forces were so strong that it caused the beam of negatively charged particles to bend. This is similar to arm wrestiling. When you arm wrestle someone bigger and stronger than you, you feel your arm bending under the force. The ray of electrons bend under the pressure of the magnetic and electric forces.
Electrons are negatively charged particles.
Negative is below zero on the number line. Atoms can't be seen and have never been seen. Scientists use models to help understand ideas that cannot be seen directly. The model of the atom was constantly changing. The next model scientists proposed looked like a ball of chocolate chip dough.