int LEDred = 12;
int LEDyellow = 4;
int LEDgreen = 7;
int buzzerPin1 = 8;

void setup() {
  // put your setup code here, to run once:
pinMode(LEDred, OUTPUT);
pinMode(LEDyellow, OUTPUT);
pinMode(LEDgreen, OUTPUT);
pinMode(buzzerPin1, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(LEDred, HIGH);
tone(buzzerPin1, 500, 500);
delay(2000);
digitalWrite(LEDred, LOW);
noTone(buzzerPin1);
digitalWrite(LEDyellow, HIGH);
tone(buzzerPin1, 500, 500);
delay(2000);
digitalWrite(LEDyellow, LOW);
noTone(buzzerPin1);
digitalWrite(LEDgreen, HIGH);
tone(buzzerPin1, 500, 500);
delay(2000);
digitalWrite(LEDgreen, LOW);
noTone(buzzerPin1);
}