Respuesta :
1.I believe the correct answer is in 16th century.
Graphite pencils were first used in 16th century when the large graphite deposit in Borrowdale, England was discovered. Graphite sticks were originally wrapped in string, but later were inserted into hollowed-out wooden sticks (in Italy). But, before graphite pencil, in ancient Rome, writers were using stylus, a thin metal rod to leave a light, but readable mark on papyrus and after that a predecessor of graphite pencile, the silverpoint.
2. I believe the correct answer is crystalline allotrope of carbon.
Graphite is a crystalline allotrope of carbon, a native element mineral, and a form of coal. Graphite is the most stable form of carbon and can be divided in four types: amorphous graphite, lump graphite (or vein graphite), highly ordered pyrolytic graphite and graphite fiber. Graphite may be used for batteries, steelmaking, brake linings, pencils etc.
3. I believe the correct answer is: hard black pencil, most standard use of pencil.
HB scale is the second (after numerical) scale for determining the characteristic of the graphite pencils. Letter “H” means that the pencil is hard and letter “B” means that the pencil is black. If the pencil would be HH it will mean that the pencil is extra hard, but if the pencil is B, it is blacker, soft pencil.
4. I believe the correct answer is: the pencil is harder.
When the letter “H” which represents the hardness of the pencil is increased, the hardness of the hardness of the pencil is increased. For example, 3H pencil is twice harder than the H graphite pencil. The same rule applies for the blackness and the softness of the graphite pencil.
Answer:
1. I believe the correct answer is in the 16th century.
2. I believe the correct answer is the crystalline allotrope of carbon.
3. I believe the correct answer is: hard black pencil, most standard use of pencil.
4. I believe the correct answer is: the pencil is harder.
Explanation:
