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.
Radioactive isotopes, also called radioisotopes, are atoms with a different number of neutrons than is usual, making them unstable.A radioisotope's nucleus decays, emitting alpha, beta and gamma rays until the isotope reaches stability.Once itâs stable, the isotope may become another element entirely, such as when uranium decays into lead.ignificance. Radioactive isotopes are useful because they produce alpha, beta and gamma rays. The radiationâs penetrating power depends on its energy, particle mass, and the objectâs density. These properties lead to many practical applications in science, medicine and industry.