Question

Which statement below is INCORRECT?

1. The sun is powered by nuclear fusion of hydrogen atoms to create helium atoms & energy.

2. In order to obtain a PET scan, a patient must ingest a radioactive material which emits positrons.

3. Nuclear reactors use controlled fission reactions of nuclear fuels (e.g., 235U) to generate electricity.

4. Archaeologists take advantage of the radioactive decay of carbon-14 nuclei to determine the age of artifacts.

5. New elements are synthesized by accelerating a heavy element to strike a light element target in a cyclotron.

Answer 1

All the given statements are true except the last statement.

A cyclotron is a particle accelerator that can be utilized for synthesizing new heavy elements that are usually so unstable that they decompose rapidly into lighter elements and are therefore cannot be isolated in nature. This synthesis of elements relies on nuclear fusion reactions and accelerate elements of low atomic mass or particles like electrons or protons or neutrons or alpha-particles at very high velocities and allow these hyper-accelerated particles to collide with a target composed usually of heavy elements of atomic mass and number slightly lower than the target element to be synthesized.

To minimize energy for acceleration and since heavier nuclei are easier targets to hit, only light nuclei are accelerated to collide with heavy nuclei and not vice versa.