- Electrons crossover from emitter to collector.
- Electrons move from emitter to base.
Solution:
Key concept: Transistor:
A junction transistor is formed by sandwiching a thin layer of P-type semiconductor between two N-type semiconductors or by sandwiching a thin layer of N-type semiconductor between two p-type semiconductors.

E - Emitter (emits majority charge carriers)
C - Collects majority charge carries
B - base (provide proper interaction between E and C)

In normal operation base-emitter is forward biased, i.e., the positive pole of emitter base battery is connected to base and its negative pole is connected to the emitter. And collector base junction is reverse biased, i.e., the positive pole of the collector base battery is connected to collector and negative pole to base. Thus, electron moves from emitter to base and crossover from emitter to collector.