There are 100 senators in the U.S. Senate as of 2014. Two senators are elected from each of the 50 states to serve a six-year term. A senator must be at least 30 years old and have been a U.S. citizen for a minimum of nine years.
The Senate is considerably smaller than the House of Representatives. The vice-president of the United States presides over the Senate, voting only to break a tie. A president pro tempore acts in that capacity in the vice-president's absence. The Senate serves as the jury in trials of impeachment. A two-thirds vote for removal of a high official dismisses that official from office. The Senate also has the power to negotiate treaties and to confirm presidential appointments.