Define octet rule. Write its significance and limitations.
Answers
Answer:
Significance of octet rule: The octet rule successfully explains the formation of chemical bonds depending upon the nature of the element. It is used to determine stability in atoms.Some limitations of the octet rule are: It cannot be applied to the nonmetals after silicon in the periodic table.
ᴀᴛᴏᴍs ᴄᴀɴ ᴄᴏᴍʙɪɴᴇ ᴇɪᴛʜᴇʀ ʙʏ ᴛʀᴀɴsғᴇʀ ᴏғ ᴠᴀʟᴇɴᴄᴇ ᴇʟᴇᴄᴛʀᴏɴs ғʀᴏᴍ ᴏɴᴇ ᴀᴛᴏᴍ ᴛᴏ ᴀɴᴏᴛʜᴇʀ (ɢᴀɪɴɪɴɢ ᴏʀ ʟᴏᴏsɪɴɢ) ᴏʀ ʙʏ sʜᴀʀɪɴɢ ᴏғ ᴠᴀʟᴇɴᴄᴇ ᴇʟᴇᴄᴛʀᴏɴs ɪɴ ᴏʀᴅᴇʀ ᴛᴏ ʜᴀᴠᴇ ᴀɴ ᴏᴄᴛᴇᴛ ɪɴ ᴛʜᴇɪʀ ᴠᴀʟᴇɴᴄᴇ sʜᴇʟʟs.
sɪɢɴɪғɪᴄᴀɴᴄᴇ ᴏғ ᴏᴄᴛᴇᴛ ʀᴜʟᴇ:
ᴛʜᴇ ᴏᴄᴛᴇᴛ ʀᴜʟᴇ sᴜᴄᴄᴇssғᴜʟʟʏ ᴇxᴘʟᴀɪɴᴇᴅ ᴛʜᴇ ғᴏʀᴍᴀᴛɪᴏɴ ᴏғ ᴄʜᴇᴍɪᴄᴀʟ ʙᴏɴᴅs ᴅᴇᴘᴇɴᴅɪɴɢ ᴜᴘᴏɴ ᴛʜᴇ ɴᴀᴛᴜʀᴇ ᴏғ ᴛʜᴇ ᴇʟᴇᴍᴇɴᴛ.
☆ʟɪᴍɪᴛᴀᴛɪᴏɴs ᴏғ ᴛʜᴇ ᴏᴄᴛᴇᴛ ᴛʜᴇᴏʀʏ:
ᴛʜᴇ ғᴏʟʟᴏᴡɪɴɢ ᴀʀᴇ ᴛʜᴇ ʟɪᴍɪᴛᴀᴛɪᴏɴs ᴏғ ᴛʜᴇ ᴏᴄᴛᴇᴛ ʀᴜʟᴇ:
(ᴀ) ᴛʜᴇ ʀᴜʟᴇ ғᴀɪʟᴇᴅ ᴛᴏ ᴘʀᴇᴅɪᴄᴛ ᴛʜᴇ sʜᴀᴘᴇ ᴀɴᴅ ʀᴇʟᴀᴛɪᴠᴇ sᴛᴀʙɪʟɪᴛʏ ᴏғ ᴍᴏʟᴇᴄᴜʟᴇs.
(ʙ) ɪᴛ ɪs ʙᴀsᴇᴅ ᴜᴘᴏɴ ᴛʜᴇ ɪɴᴇʀᴛ ɴᴀᴛᴜʀᴇ ᴏғ ɴᴏʙʟᴇ ɢᴀsᴇs. ʜᴏᴡᴇᴠᴇʀ, sᴏᴍᴇ ɴᴏʙʟᴇ ɢᴀsᴇs ʟɪᴋᴇ xᴇɴᴏɴ ᴀɴᴅ ᴋʀʏᴘᴛᴏɴ ғᴏʀᴍ ᴄᴏᴍᴘᴏᴜɴᴅs sᴜᴄʜ ᴀs xᴇғ②, ᴋʀғ ② ᴇᴛᴄ.
(ᴄ) ᴛʜᴇ ᴏᴄᴛᴇᴛ ʀᴜʟᴇ ᴄᴀɴɴᴏᴛ ʙᴇ ᴀᴘᴘʟɪᴇᴅ ᴛᴏ ᴛʜᴇ ᴇʟᴇᴍᴇɴᴛs ɪɴ ᴀɴᴅ ʙᴇʏᴏɴᴅ ᴛʜᴇ ᴛʜɪʀᴅ ᴘᴇʀɪᴏᴅ ᴏғ ᴛʜᴇ ᴘᴇʀɪᴏᴅɪᴄ ᴛᴀʙʟᴇ. ᴛʜᴇ ᴇʟᴇᴍᴇɴᴛs ᴘʀᴇsᴇɴᴛ ɪɴ ᴛʜᴇsᴇ ᴘᴇʀɪᴏᴅs ʜᴀᴠᴇ ᴍᴏʀᴇ ᴛʜᴀɴ ᴇɪɢʜᴛ ᴠᴀʟᴇɴᴄᴇ ᴇʟᴇᴄᴛʀᴏɴs ᴀʀᴏᴜɴᴅ ᴛʜᴇ ᴄᴇɴᴛʀᴀʟ ᴀᴛᴏᴍ. ғᴏʀ ᴇxᴀᴍᴘʟᴇ: ᴘғ⑤, sғ⑥, ᴇᴛᴄ. )
(ᴅ) ᴛʜᴇ ᴏᴄᴛᴇᴛ ʀᴜʟᴇ ɪs ɴᴏᴛ sᴀᴛɪsғɪᴇᴅ ғᴏʀ ᴀʟʟ ᴀᴛᴏᴍs ɪɴ ᴀ ᴍᴏʟᴇᴄᴜʟᴇ ʜᴀᴠɪɴɢ ᴀɴ ᴏᴅᴅ ɴᴜᴍʙᴇʀ ᴏғ ᴇʟᴇᴄᴛʀᴏɴs. ғᴏʀ ᴇxᴀᴍᴘʟᴇ, ɴᴏ ᴀɴᴅ ɴᴏ② ᴅᴏ ɴᴏᴛ sᴀᴛɪsғʏ ᴛʜᴇ ᴏᴄᴛᴇᴛ ʀᴜʟᴇ.
(ᴇ) ᴛʜɪs ʀᴜʟᴇ ᴄᴀɴɴᴏᴛ ʙᴇ ᴀᴘᴘʟɪᴇᴅ ᴛᴏ ᴛʜᴏsᴇ ᴄᴏᴍᴘᴏᴜɴᴅs ɪɴ ᴡʜɪᴄʜ ᴛʜᴇ ɴᴜᴍʙᴇʀ ᴏғ ᴇʟᴇᴄᴛʀᴏɴs sᴜʀʀᴏᴜɴᴅɪɴɢ ᴛʜᴇ ᴄᴇɴᴛʀᴀʟ ᴀᴛᴏᴍ ɪs ʟᴇss ᴛʜᴀɴ ᴇɪɢʜᴛ. ғᴏʀ ᴇxᴀᴍᴘʟᴇ, ʟɪᴄʟ, ʙᴇʜ ②, ᴀʟᴄʟ③ ᴇᴛᴄ. ᴅᴏ ɴᴏᴛ ᴏʙᴇʏ ᴛʜᴇ ᴏᴄᴛᴇᴛ ʀᴜʟᴇ.