2. which minerals contain the two most abundant elements by mass in earths
a. fluorite and calcite
b. magnetite and pyrite
c. amphibole and quartz
d. galena and sulfur

Compare and contrast physical changes with chemical changes.

Compare and contrast the bohr model and the electron cloud models of the atom.

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.