Students in chemistry course were asked the following question on a unit exam: "Draw a diagram representing an element using circles as atoms."
a. The following diagrams represent the two types of answers given by students. Which is the drawing best representation of an element? Explain.
b. imagines that the atom in drawing B had been removed from one of the substances used earlier.
i. List the codes of the substances that "drawing B" could have come from through physical separations?

I need more help with part b. plz

Drive down any three characteristic of modern periodic table

Ase your answer to this question on the information below. hydrocarbons and fissionable nuclei are among the sources used for the production of energy in the united states. a chemical reaction produces much less energy than a nuclear reaction per mole of reactant. the balanced chemical equation below represents the reaction of one molecule of a hydrocarbon with two molecules of oxygen. chemical equation: ch4 + 2o2 → co2 + 2h2o + 1.48 × 10−18 jthe nuclear equation below represents one of the many possible reactions for one fissionable nucleus. in this equation, x represents a missing product. nuclear equation: write an isotopic notation for the missing product represented by x in the nuclear equation.

Consider this equilibrium: n29) + o2(g) + 2no(c).nitrogen gas and oxygen gas react when placed in a closed container. as the reaction proceeds towards equilibrium, what happens to the rate of thereverse reaction?