<u>c.</u> 12. preparing data tables and gathering safety equipment
<u>b.</u> 13. reading all instructions before beginning a science lab
<u>a.</u> 14. recognizing what a picture of a hand means
<u>e.</u> 15. wiping your work area with a wet paper towel
<u>d.</u> 16. wearing goggles and an apron
Answer:
I believe it is A
Explanation:
pH = -log[H+] and pOH = -log[OH−].
C. HNO₃(aq) + KOH(aq) → KNO₃(aq) + H₂O
Answer:
4 sun , planet, moon are the components in the correct order
<h3>
Answer:</h3>
6.25 atoms
<h3>
Explanation:</h3>
<u>We are given</u>;
- The half life of Po-218 is 3 minutes
- Initial sample is 200 atom
- Time of decay is 15 minutes
We are required to calculate the remaining mass after decay;
Half life refers to the time taken for original amount of a radioactive sample to decay to a half.
To calculate the remaining mass we use the formula;
N = N₀ × 0.5^n where n is the number of half lives, N is the new amount and N₀ is the original amount.
n = 15 min ÷ 3 min
= 5
Therefore;
New amount = 200 atom × 0.5^5
= 6.25 atoms
Therefore; the amount of the sample that will remain after 15 minutes is 6.25 atoms.
