Asubstance undergoes a change. which of the following indicates that the change was a chemical change? the substance changed shape. new molecules formed. the substance froze. the substance changed size.

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

Plzz a sample of table sugar (sucrose, c12h22o11) has a mass of 7.801 g. ● a) calculate the number of moles of c12h22o11 in the sample b) calculate the number of moles of each element in c12h22o11 (number of moles of c, number of moles of h & number of moles of o) in the sample. (use your answer from part a as your starting point.) show your work and highlight your final answer. calculate the number of atoms of each element in c12h22o11 (number of atoms of c, number of atoms of h & number of atoms of o) in the sample. (use your answers from part b as your starting for each element.) show your work and highlight your final answer.