LOS ANGELES, Feb 7: Canadian pop star Justin Bieber became the youngest artist to land five chart-topping albums in the United States on Wednesday when his latest record, “Believe Acoustic,” debuted atop the Billboard 200 album chart. “Believe Acoustic,” which features stripped down versions of Bieber’s songs from his fourth No. 1 album, “Believe,” released last June, as well as three new songs, sold 211,000 copies in its first week according to figures from Nielsen SoundScan. (agencies)