4Fe + 3O2à 2Fe2O3 is a balanced equation. What is the charge on each iron (Fe) ion in hematite (Fe2O3) ?

A. + 1

B. + 2

C. + 3

D. + 4

Which equation shows conservation of mass? A. H2O → H2 + O2 B. PCl5 → PCl3 + Cl2 C. Na + Cl2 → NaCl D. Al + Br2 → AlBr3

Is the expansion of chlorine a physical or chemical change?

Which is a way you would expect two animals of the same species to differ? A. the majority of their genetic material B. their ability to reproduce with one another c. the size of animals that reach adulthood D. their physical traits such as coloring

Write some facts about the Atmosphere

Why is it impossible to perform a liquid-liquid extraction using h2o (water) and ch3oh (methanol) ?

What happens to the velocity of a sound wave in air if the temperature of the air increases

Determine the [oh-] concentration of a 0.741 m koh solution at 25°c.

In the lab, students decomposed a sample of calcium carbonate by heating it over a Bunsen burner and collected carbon dioxide according to the following equation: CaCO3 (s) CaO (s) CO2 (g) (a) How many mL of carbon dioxide gas were generated by the

J. J. Thomson A) Electrons are in orbital levels. John Dalton B) Atoms are the smallest unit of an element. Ernest Rutherford C) Electrons are scattered within the atom. Niels Bohr D) Protons are at the center of an atom.

Which answer best describes an alloy