Question

Modern periodic table is the extension of original​

Answer 1

Answer:

ᴛʜɪꜱ ᴍᴏᴅᴇʀɴ ᴩᴇʀɪᴏᴅɪᴄ ᴛᴀʙʟᴇ ɪꜱ ᴛʜᴇ ᴇxᴛᴇɴꜱɪᴏɴ ᴏꜰ ᴛʜᴇ ᴏʀɪɢɪɴᴀʟ ᴍᴇɴᴅᴇʟᴇᴇᴠ'ꜱ ᴩᴇʀɪᴏᴅɪᴄ ᴛᴀʙʟᴇ ᴀɴᴅ ᴋɴᴏᴡɴ ᴀꜱ ᴛʜᴇ ʟᴏɴɢ ꜰᴏʀᴍ ᴏꜰ ᴩᴇʀɪᴏᴅɪᴄ ᴛᴀʙʟᴇ. ɪɴ 1913, ᴛʜᴇ ᴇɴɢʟɪꜱʜ ᴩʜyꜱɪᴄɪꜱᴛ ʜᴇɴʀy ᴍᴏꜱᴇʟᴇy, ᴛʜʀᴏᴜɢʜ ʜɪꜱ x-ʀᴀy ᴅɪꜰꜰʀᴀᴄᴛɪᴏɴ ᴇxᴩᴇʀɪᴍᴇɴᴛꜱ, ᴩʀᴏᴠᴇᴅ ᴛʜᴀᴛ ᴛʜᴇ ᴩʀᴏᴩᴇʀᴛɪᴇꜱ ᴏꜰ ᴇʟᴇᴍᴇɴᴛꜱ ᴅᴇᴩᴇɴᴅ ᴏɴ ᴛʜᴇ ᴀᴛᴏᴍɪᴄ ɴᴜᴍʙᴇʀ ᴀɴᴅ ɴᴏᴛ ᴏɴ ᴛʜᴇ ᴀᴛᴏᴍɪᴄ ᴍᴀꜱꜱ.

Answer 2

Answer:

The modern periodic table is used to organize all the known elements. Elements are arranged in the table by increasing atomic number. ... Atomic numbers increase from left to right and from top to bottom in the table. Rows of the periodic table are called periods.