Question

Which of the following has the highest density?
A.$Fe$
B.$Ca$
C.$B$
D.$Pb$

Answer 1

Hint: Density of an element is defined as the amount of mass contained in that element, per unit volume. It is measured in the units of $gc{m^{ - 3}}$, at room temperature.

Complete step by step answer:
Density is a periodic property and thus follows a general trend in periodic table. On moving from top to bottom, atomic density increases and while moving from left to right across the period, it varies less significantly. Values of density for all the elements present in the periodic table are shown relative to the density of osmium, osmium being the element with highest density.
As per the data, densities for following elements are as follows-
$Fe = 7.874gc{m^{ - 3}}$
$Ca = 1.55gc{m^{ - 3}}$
$B = 2.46gc{m^{ - 3}}$
$Pb = 11.34gc{m^{ - 3}}$
Clearly, lead ( $Pb$) is the most dense element among these four.

So, the correct option is D.

Note:
-Lead has got its wide application in car batteries, ammunition, cable sheathing, pigments, weights used for lifting, weight belts used in diving and radiation protection.
-The most widely used metal today is iron. Almost 90% of all the metals that are being refined today are iron. It is widely used in industries for manufacturing steel and certain alloys. It is also used in civil engineering for reinforced concrete, girders etc .
-Boron is found in food items such as nuts. People often consume supplements of boron as a medicine. It is also used to treat vaginal yeast infections, for weak or brittle bones. Infact, between 1870 and 1920. It was used as a preservative.