I think it is Para-position.
Answer: 289.1 torr ..........
Lesser. atomic number means proton number
Volume perhaps ?
Hope this helps !
<span> the atmosphere holds about 21 per cent oxygen. Over the Earth’s 4.6 billion year history, oxygen did not appear in the atmosphere until perhaps about 2.5 billion years ago. Since then, oxygen levels have fluctuated in tandem with global geological and biological events, such as mass extinctions.</span>
