QUESTION: What is made of gold, silver, copper and nickel and is thrown away every day?Answer: the mobile phone.Recently St Patrick's Primary School children did their bit to reduce the number of phones that end up in land fill. The school took part in a national recycling program, the Mobile Muster. St Patrick's enrolment of 218 pupils managed to round up more than 400 handsets for recycling as part of the muster.That effort put them at the top of the pile of participating Victorian schools and second among schools along the eastern seaboard. Better yet, for every mobile phone they mustered, Landcare Australia will plant a tree. "This meant that our school was responsible for the planting of more than 400 trees," Coordinating teacher Cathy Whelan said. Muster organisers estimate three out of four people have at least one old, unused mobile phone at home.Aside from the precious metals and plastic, mobiles also contain small amounts of potentially hazardous substances, such as cadmium in NiCad batteries. The school had recently joined the Educating for a Sustainable Environment Network through the Catholic Education Office, principal Anthony Clifford said.