Texas Instruments TMP100 (I2C) 7 bit slave address + 1 bit for READ(1)/write(0)

Using Arduino Sensors
4

Not quite. You send a command and then receive a reply.

void setup()
    {
     Wire.begin();
    }

void loop()
{
    // Send the register address
     Wire.startTransmission(Tmp_add);
     Wire.write(pointer_register);
     Wire.endTransmission();

     // Request the data
     Wire.requestFrom(Tmp_add,1);
     int register_value = Wire.read();
}