How many atoms of gold are present in a 250 kg sample of sylvanite? Group of answer choices

7.18 X 10^25 Au atoms

6.02 X 10^23 Au atoms

5.18 X 10^25 Au atoms

4.49 X 10^26 Au atoms

1. list three scientific reasons cockroaches may fly.

An electron moved from shell n = 2 to shell n = 1. what most likely happened during the transition? a fraction of a photon was added. a photon of energy was absorbed. a fraction of a photon was removed. a photon of energy was released.

What does a complete balanced chemical equation include? a. exothermic coefficients b. endothermic coefficients c. valence electrons d. molar coefficients