Decide which element probably has a density most and least similar to the density of potassium. Comparing density: lead rubidium thallium xenon
most similar to potassium
least similar to potassium

most similar to potassium   = rubidium

least similar to potassium  = thallium

Explanation:

The density of an element is the number of particles per unit volume. To determine the element with the most probable density and the least density, we need to know their density values.

For potassium, density = 0.862 g/cm³

Density of lead = 11.35 g/cm³

Density of rubidium = 1.63 g/cm³

Density of thallium = 11.85 g/cm³

Density of xenon = 5.9  g.cm³

So from their density values, the density that has the most similar density to potassium is rubidium.

The element that is least similar to potassium is thallium.

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