This painting of an alchemist’s laboratory was made around 1570 This painting of an alchemist’s laboratory was made around 1570. For centuries, these early scientists, known as alchemists, tried to use chemical reactions to make gold. The alchemists failed in their attempts to turn lead into gold.

Nuclear Reactions in the Laboratory How do artificial transmutations occur? Transmutation is the conversion of atoms of one element to atoms of another. Scientists can perform artificial transmutations by bombarding atomic nuclei with high-energy particles such as protons, neutrons, or alpha particles.

Nuclear Reactions in the Laboratory Transmutation involves a nuclear change, not a chemical change. Nuclear decay is an example of a transmutation that occurs naturally. Transmutations can also be artificial.

Nuclear Reactions in the Laboratory In 1919, Ernest Rutherford performed the first artificial transmutation by exposing nitrogen gas to alpha particles. Some of the alpha particles were absorbed by the nitrogen nuclei. Each newly formed nucleus then ejected a proton, leaving behind the isotope oxygen-17.

Transuranium Elements How are transuranium elements produced? Elements with atomic numbers greater than 92 (uranium) are called transuranium elements. Scientists can synthesize a transuranium element by the artificial transmutation of a lighter element.

Nuclear Reactions in the Laboratory All transuranium elements are radioactive, and they are generally not found in nature. Neptunium was the first transuranium element synthesized. In 1940, scientists at the University of California, Berkeley, bombarded uranium-238 with neutrons, producing uranium-239. The uranium-239 underwent beta decay to form neptunium-239.

Nuclear Reactions in the Laboratory Most transuranium elements have only been produced for research, but some are synthesized for industrial use. Americium-241 is a transuranium element used in smoke detectors. The decay of plutonium-238 is used to generate electrical energy in some space probes.

Nuclear Reactions in the Laboratory In 1977, NASA launched Voyager 1 and Voyager 2 spacecraft to explore the outer solar system. They are powered by the alpha decay of plutonium-238.

Particle Accelerators Some transmutations require particles that are moving at extremely high speeds. Particle accelerators cause charged particles to move very close to the speed of light. The fast-moving particles collide with atomic nuclei. Scientists have produced more than 3000 different isotopes.

Particle Accelerators Scientists also conduct collision experiments in order to study nuclear structure. More than 200 different subatomic particles have been detected. A quark is a subatomic particle theorized to be among the basic units of matter. According to the current model of the atom, protons and neutrons are made up of quarks.

Particle Accelerators This particle detector records subatomic particles produced in the Tevatron, the most powerful particle accelerator in the world. The Tevatron is located at Fermilab in Batavia, Illinois.

Which of the following is a type of atom transmutation? Assessment Questions Which of the following is a type of atom transmutation? alpha decay gamma decay chemical reaction ionization

Which of the following is a type of atom transmutation? Assessment Questions Which of the following is a type of atom transmutation? alpha decay gamma decay chemical reaction ionization ANS: A

Assessment Questions To study the structure of the atomic nucleus, scientists use particle accelerators to combine small nuclei into larger nuclei. cause chemical reactions to occur rapidly. cause collisions of particles moving near the speed of light. magnify nuclei so they can be studied on a computer monitor.

Assessment Questions To study the structure of the atomic nucleus, scientists use particle accelerators to combine small nuclei into larger nuclei. cause chemical reactions to occur rapidly. cause collisions of particles moving near the speed of light. magnify nuclei so they can be studied on a computer monitor. ANS: C

Assessment Questions Scientists make transuranium elements by the artificial transmutation of lighter elements. True False

Assessment Questions Scientists make transuranium elements by the artificial transmutation of lighter elements. True False ANS: T