The language of the presidential oath is specified in Article II, Section I of the U.S. Constitution:

"I do solemnly swear (or affirm) that I will faithfully execute the Office of the President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."

The president-elect traditionally takes the oath with his hand on a Bible. However, this is not a requirement -- Theodore Roosevelt took the oath in 1901 without swearing on a Bible.

The vice-president-elect takes the same oath as other federal employees:

"I do solemnly swear that I will support and defend the Constitution of the United States against all enemies, foreign and domestic, that I will bear true faith and allegiance to the same, that I take this obligation freely, without any mental reservation or purpose of evasion, and I will well and faithfully discharge the duties of the office on which I am about to enter. So help me God."