The top three U.S. exports to China in 2008 were electrical machinery ($9.5 billion), oil seeds and related products ($9.3 billion), and nuclear reactors and related machinery ($8.4 billion). China is now one of the most important markets for U.S. exports: in 2009, U.S. exports to China totaled $69.6 billion, a 0.2% decrease from 2008. Those percentages were down far less than U.S. exports to other major trading partners in the year following the global financial crisis.
Return to questions. 1) A positively charged particle made up of two protons and two neutrons and released by a radioactive nucleus is the alpha particle. 2) An electron released by a radioactive nucleus that causes a neutron to change into a proton is called a beta particle.3) The amount of time for half the atoms in a radioactive sample to decay is called the half-life.eturn to questions. 1) A positively charged particle made up of two protons and two neutrons and released by a radioactive nucleus is the alpha particle. 2) An electron released by a radioactive nucleus that causes a neutron to change into a proton is called a beta particle.
Some materials are radioactive because the nucleus of each atom is unstable and can decay, or split up, by giving out nuclear radiation in the form of alpha particles, beta particles or gamma rays. The nuclear radiation given off can be detected using a Geiger counter.