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.
When Uranium, atomic number 92, loses a proton, it is no longer uranium. It is Protactinium, atomic number 91. When it loses another proton, it becomes thorium, Atomic number 90. As the big, unstable atoms decay into smaller atoms, they shoot off high speed particles of various kinds, plus radioactive energy. The process of decay proceeds step by step at a definite rate. After 4.5 billion years, half a supply of radioactive uranium has decayed into a type of lead, whose atomic number is 82.