<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>
Answer:
Cells are the smallest living unit of an organism
I think it's the minimum required energy to the reaction to occur
Answer:
The volume of the gas got doubled.
Explanation:
Charle's law states that the volume of an ideal gas is direclty proportional to the absolute temperature.
Thus, V ∝ T
Or,
<u>If the bottle is heated to the double of the temperature, the volume of the gas also gets doubled.</u>