Lise Meitner was an Austrian physicist who was the first woman to become a full professor of physics in Germany - Leaving Cert Physics - Question 12 - 2021

The control rods are designed to absorb excess neutrons and regulate the rate of the fission reaction. By adjusting the position of these rods within the reactor core, operators can control the amount of fission that occurs, ensuring the reaction remains stable and safe.

The purpose of shielding is to protect personnel and the environment from harmful radiation emitted during the fission process. Shielding materials, such as lead, concrete, or water, are commonly used to reduce radiation exposure by preventing radiation from escaping the reactor core.

One disadvantage of nuclear fission is the generation of radioactive waste, which poses significant disposal and environmental challenges. Additionally, there is always the risk of nuclear accidents, which can have catastrophic consequences.

In an atom of meitnerium (Mt), there are 109 electrons. This is equal to the atomic number of the element, which dictates the number of protons and hence the electron count in a neutral atom.

Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation. This can occur in the form of alpha particles, beta particles, or gamma rays as the atom transitions to a more stable state.

Gamma radiation is the most penetrating type of nuclear radiation. It can easily pass through most materials, including human tissue, and requires dense shielding such as lead or thick concrete to reduce its intensity.

An experiment to compare the penetrating power of alpha, beta, and gamma radiation can be conducted using a radiation source and different shielding materials. Place a Geiger counter behind varying thicknesses of materials (such as paper, plastic, and lead) and measure the count rate for each type of radiation. This will illustrate how each type interacts with matter, with results showing that alpha radiation can be stopped by a sheet of paper, beta radiation by plastic, and gamma radiation requires significantly denser materials.

Isotopes are variations of a chemical element that have the same number of protons but different numbers of neutrons in their nuclei. This results in different atomic masses, though the isotopes exhibit similar chemical properties.

To find the number of neutrons in the isotope Cm²⁴⁷, subtract the atomic number (96 for curium) from the mass number (247).

Thus, the calculation is:

$247 - 96 = 151$

Therefore, there are 151 neutrons in the isotope Cm²⁴⁷.