Is testing for fingerprints on a door a physical or chemical change

What is a silicon-oxygen tetrahedron and how many of each element is in it?

If methyl benzoate is the limiting reagent, and 1.3 g of methyl benzoate were used for this reaction, what is the theoretical yield of the mono nitration reaction? (hint: the product formula is C8H7O4N)

imagine sulfur, s, is 72% sulfur-32 and 28% sulfur-33 determine the average atomic mass of sulfur in this scenario

The compound ncl3 is nitrogen trichloride, but alcl3 is simply aluminum chloride. why

Which statement describes how technology has increased our information on Mars? The Curiosity rover found sulfur compound in rocks. The Curiosity rover located methane in soil samples. The Curiosity rover detected carbon in organic molecules.

Two clear solutions are placed in separate beakers. The first solution has a pH of 4, and the pH of the second solution is unknown. If the two solutions are mixed and the resulting pH is 5, the second solution must have

Based on its location on the periodic table, which element (s) have properties similar to N? Choose all that apply. * P C O Bi

What conclusion can be drawn from the statement that an element has low electron affinity, low electronegativity, and a low ionization energy?

A scientist performs an experiment in which a radium-226 (Ra-226) atom decays into radon-222 (Rn-222). The scientist concludes that some energy must have been added to the system to cause this reaction to begin.

Which suitable method can be used to separate a mixture of sand and paraffin