Simple NPN Transistor switch control with cooling fan

1int Fan = 7;
2
3int BAUD = 9600;
4void setup() {
5  // put your  setup code here, to run once:
6pinMode(Fan, OUTPUT);
7
8Serial.begin(9600);
9delay(1000);
10Serial.println("START");
11}
12
13void  loop() {
14  // put your main code here, to run repeatedly:
15digitalWrite(Fan  , HIGH);
16delay(5000);
17digitalWrite(Fan, LOW);
18delay(5000);
19}
20