SiO2 has a melting point of 1700°C, whereas CO2 has a melting point of -78°C. What is the reason for this huge difference between two elements in the same group?​

The difference is because SiO2 is solid while CO2 is gaseous

The difference is the melting point values despite belonging to the same group is their STATE OF MATTER.

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the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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