Only 170,000 Arabs who lived in what would become Israeli-held territory after the war prior to the war in 1948 remained in Israel after 1948. (The phrasing is convoluted since the borders of Israel were only established after the 1948 war, however, if we use those same borders and extrapolate them into the past, this is where the 170,000 number comes from. Note also that this number does not count Druze, Bedouins, Circassians, Armenians, and any other non-Jewish minority that does not identify as Palestinian).
Since the question does not ask about it, this question will not deal for the reasons behind that departure. More on that can be read at the Related Question below.
It is also worth noting that 170,000 Israeli Arabs who remained in Israel in 1949 have now blossomed into a population of more than 1.6 million individuals. Please see the comment section for more information on other ambiguities.
170,000
Ethnic Palestinians.
Israeli
It is unclear what is meant by "in Israel". If that is referring to territory under Israeli control, then the PLO/PA qualifies. If it is referring to the territory under Israeli control in 1949, then Hamas and Islamic Jihad qualify.
Yes. Being Arab is an ethnicity, while being Israeli is a nationality. 20% of Israelis are Arabs.
Israeli is the common term. However, I know Israeli Arabs who would prefer to be called Palestinians, and before 1948, Jews from the region now known as Israel were known as Palestinian Jews.
The Arabs and the Israelis.
Israel declared independence in 1948, but only established full control of its territory in April of 1949, when it was victorious in the Arab-Israeli War of 1948-9, which the Israelis call the Israeli Independence War and the Arabs called the Nakba or Catastrophe.
Since 20% of Israelis are Arabs, the two groups have some overlap, but if the question refers exclusively to non-Israeli Arabs and Israelis, there is a tense and violent political and economic relationship. On a personal level, there are some Arab-Israeli relationships.
Israeli Arabs have the same rights as Israeli Jews and therefore can choose to live wherever they want within Israel or Area C in the West Bank. Unlike Jews however they can also settle in Areas B and A where Jews are prohibited to enter by law. However few Arabs choose to live in settlements, except for Ariel where many Arabs study in the Shomron Academic Center, and few Jews in Judea and Samaria would like to have Arabs for neighbors.
It depends on who you mean by "the Arabs". If you are referring to Arab citizens of any state, even Israel, then most Arab land-holdings are in the Galilee region in the north of Israel, although there is a significant Arab population with land-holdings in Haifa, Acre, and Jerusalem. If you are referring to Arab governments, the Arabs own no territory in the State of Israel. Hamas controls the Gaza Strip and the Palestinian Authority controls parts of the West Bank, neither of which are in sovereign Israeli territory.
because it was a muslim territory and and before that the arabs had a different belief.