Which of the following best describes the physical properties of hydrogen?

The correct characterization of hydrogen's physical properties is that it is colorless, odourless, and tasteless. These attributes are crucial for identifying hydrogen in various applications and understanding its behavior. Being colorless means it cannot be seen with the naked eye, which is significant for safety considerations since leaks may go unnoticed. The odorless nature of hydrogen implies that it does not have a smell, making it difficult to detect without specialized equipment; this adds to the importance of monitoring systems in environments where hydrogen is present to prevent accidents.

Additionally, hydrogen’s tastelessness means that it cannot be detected through taste, reinforcing the need for detection systems in scenarios where it might be released. Understanding these properties helps in recognizing hydrogen as a key component in various chemical processes, fuel cells, and as a potential energy source.