Diamond is the hardest substance known while graphite is one of the softest. both are made only of carbon atoms. what is the most likely reason why this is true? a. both are bonded ionically. b. both are bonded covalently. c. the carbon atoms are arranged differently in diamond than in graphite. d. the carbon atoms in diamond are bonded to each other but in graphite there are no bonds.

The correct answer is C. The carbon atoms are arranged differently in diamond than in graphite.

Explanation:

Diamond and graphite are solid and different structures despite being formed by carbon atoms.

In the case of graphite, the C atoms exhibit sp² hybridization. This means that each carbon atom is linked to another 3 by a covalent bond,  forming laminar structures (that is, sheets of carbon atoms are formed.).

In the diamond, the C atoms exhibit a sp³ hybridization, each one joining 4 other C atoms through a covalent bond and forming a three-dimensional structure.

This difference in structures explains that graphite is one of the softest materials, because the links between the sheets are very weak and it is easily exfoliable while diamond is the hardest substance known due to precisely that three-dimensional structure of covalent bonds.

Finally, the correct answer is C. The carbon atoms are arranged differently in diamond than in graphite.

answer: c.

explanation:

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).