19. (1 point) balance the following chemical equation: fe o₂ → fe₂o₃ what is the coefficient on fe, o₂ and fe₂o₃ *
1, 2, 3
4, 3, 2
1, 3, 1
2, 1, 1
20. (1 point) the law of conservation of mass lets us know that in every chemical equation you have to have the same number of on both sides of the equation. *
moles
coefficients
atoms of each element
molecules
21. (1 point) in order for the reaction: ca cuso₄ → cu caso₄ to occur, which of the following must be true? *
cu must be above ca on the activity series.
ca must be above cu on the activity series.
heat must be applied to the reaction.
none of the above

Amass of 100.0 g of solute is dissolved in water so that 850. ml of a 0.7500 m solution has been prepared. what is the molar mass of the solute?

The table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of tthe table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 9 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.

How do dying stars contribute to the formation of planets