Potassium-40 has a half life of 1.251×billion<span> years</span><span>. To determine the percentage potassium-40 remaining after 3.9 billion years, divide
3.9 by 1.251, = 3.12.
This is the number of times the original amount of potassium-40 reduces by 50%. The remaining percentage is therefore 100%/(3.12 * 2) = 16.03%.</span>
If CPR is not performed, C. 4 minutes will elapse before the brain becomes damaged from lack of oxygen.
One minute isn't enough time - you can even hold your breath for one minute without fainting. Some people can even do it for 2 minutes.
Ten minutes is too long - you would be long dead.
Answer:
The cell wall is a rigid non-living layer that is found outside the cell membrane and surrounds the cell
Explanation:
The answer is B and I need 20 characters so I am typing random words
