In a sample of 1000 atoms of an unknown element, it is found that 14 are isotopes of mass 203.973 amu, 241 are isotopes of mass 205.9745, 221
are isotopes of mass 206.9759, and the remaining 524 are isotopes of
mass 207.9766 amu.
1. Calculate the average atomic mass of the unknown substance. Answer
with four decimal places
1. Determine the identity of the unknown element.

Select the correct answer. given: 2libr + ba → babr2 + 2li in this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced? a. 1.18 mol b. 2.37 mol c. 4.73 mol d. 16.4 mol e. 32.9 mol

What are the spectator ions in 2h+ + so42- + ca2+ + 2r → caso4 + 2h+ + 21?

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.