8 seconds have passed. There is a sample of lithium-8 being tested. The half-life of lithium-8 is 0.84 seconds. The sample of lithium-8 after 8 seconds is 28 grams. How much lithium-8 was in the sample at the beginning of the experiment? Round your answer to 2 sig figs.
Do no forget units!

7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation. 8. when a 2.5 mol of sugar (c12h22o11) are added to a certain amount of water the boiling point is raised by 1 celsius degree. if 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? show all calculations leading to your answer or use 3 – 4 sentences to explain your answer. 9. if 5.40 kcal of heat is added to 1.00 kg of water at 100⁰c, how much steam at 100⁰c is produced? show all calculations leading to an answer. 10. the freezing of water at 0⁰c can be represented as follows: h2o (l) ↔ h2o(s) the density of liquid water is 1.00 g/cm3. the density of ice is 0.92 g/cm3. in 3 – 4 sentences explain why applying pressure causes ice to melt.

The missing component to the table to the right or indicated with orange letters complete the table by filling in the corresponding numbers or symbols

How do dying stars contribute to the formation of planets