Which tribes were lost

The phrase "Ten Lost Tribes" does not appear in the Bible, leading some to questions the actual number of tribes involved. However, 1 Kings 11:31 states that the LORD will tear the kingdom out of the hand of Solomon and give ten tribes to Jeroboam:
" And he said to Jeroboam, Take thee ten pieces: for thus saith the LORD, the God of Israel, Behold, I will rend the kingdom out of the hand of Solomon, and will give ten tribes to thee". (1 Kings 11:31}
" But I will take the kingdom out of his son's hand, and will give it unto thee, even ten tribes." (1 Kings 11:35)
However, it is not clear which tribes are to be counted as lost. The tribes which have been lost are those which formed the Kingdom of Israel following the dissolution of the united Kingdom of Israel in c. 930 BCE. The tribes of Reuben, Issachar, Zebulun, Dan, Naphtali, Gad, Asher, Ephraim and Manasseh were parts of the kingdom, a total of nine.
It has sometimes been said that the Tribe of Simeon was a part of the northern Kingdom of Israel and was therefore part of the "Ten Lost Tribes." However, the Tribe of Simeon was never located in the Northern Kingdom, but was located entirely within the land of Judah. (Joshua 19:1) Apparently, Simeon's tribal distinctions were lost shortly after Canaan was settled by the Israelites when the Simeonites assimilated into the Tribe of Judah.[citation needed]