Question
Question: Percentage of lead in a lead pencil is: A. zero B. 20 C. 80 D. 70...
Percentage of lead in a lead pencil is:
A. zero
B. 20
C. 80
D. 70
Solution
Lead is an element with its Latin name Plumbum. The symbol of lead is Pb and its atomic number is 82. It is a heavy metal with high density. The color of lead is silvery with a hint of blue. So first we have to find the components that make up a lead pencil and their percentages. From this we need the percentage of lead in it.
Complete answer: We are given to find the percentage of lead in a lead pencil.
Lead is a metal which belongs to the 14th group and a p-block element. Lead is a soft malleable metal with high density. It is mostly used in making batteries such as Lead-acid batteries. It is a very reactive metal.
So to make a lead pencil, we need graphite not lead. Graphite is a form of carbon and Graphite is mixed with clay and formed into lead pencils. Graphite is a non-toxic material.
So as there is no lead present in lead pencils, the percentage of lead in a lead pencil is obviously zero.
Hence, the correct option is Option A, zero.
Note: As we can see, there is a word “lead” in lead pencil, but actually there will be no lead present in lead pencils. So do not get misconceived that as the name lead-pencil has the word “lead” in it, the object will also have the component in it. One more example is that Iceland is a country which has greenery and Greenland is a country which is covered with ice.