Explanation
On the Arduino Uno, the pin utilized for SCL (Serial Clock) in an I2C (Inter-Integrated Circuit) connection is analog pin A5. On the Arduino Uno, A4 is used for SDA (Serial Data), and A5 is used for SCL. When working with I2C devices, it's common to connect them to these specific pins to establish communication.
To summarize:
SDA (Serial Data) is connected to A4 on the Arduino Uno.
SCL (Serial Clock) is connected to A5 on the Arduino Uno.