निम्नलिखित में से किसने जोसेफ प्रिस्टले के प्रकाशन से पहले, लगभग 1772 में स्वतंत्र रूप से ऑक्सीजन गैस की खोज की थी?

Joseph Priestley was the first to report the discovery of which element and describe some of its extraordinary properties in 1774?

In which year was chlorine gas first discovered by Carl Wilhelm Scheele?

Which of the following scientists is famously credited with the discovery and isolation of the radioactive element radium?