How did modern scientists experiment with Van Gogh's paints to determine their chemical reactions? 1. They used X-ray analysis.
2. They used litmus testing.
3. They burned the paint to examine what elements were left after the chromium was burned off.
4. They studied the density of modern yellow paint to that of 100-year-old paint.

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.

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a