Answer:
For 7: The correct answer is c.
For 8: The correct answer is d.
Explanation:
For 7:
Binary molecular compounds are defined as the compounds formed from the combination of only two elements. Examples are:
etc..
These compounds are formed when two non-metal elements combine together. The first element contains partial positive charge and second element contains partial negative charge.
Hence, the correct option is c.
For 8:
For the naming of binary molecular compounds, we use the prefix to indicate how many of each element is present in the compound.
For 1' we use 'mono', for '2' we use 'di', for '3' we use 'tri', for '4' we use 'tetra', for '5' we use 'penta', for '6' we use 'hexa', for '7' we use 'septa', for '8' we use 'octa', for 9 we use 'nona' and for '10' we use 'deca'.
Hence, the correct option is d.