Final answer:
The statement is true; Marie Curie's work on radioactivity was indeed conducted in a highly competitive scientific environment with many other scientists also working on the subject. Her achievements, including Nobel Prizes in Physics and Chemistry, underscore the significance of her contributions.
Step-by-step explanation:
It is true that Marie Curie's work on radioactivity was highly competitive. Many other scientists of her time were also researching this new and exciting phenomenon. Marie Curie coined the term "radioactivity" and alongside her husband Pierre Curie and Henri Becquerel, contributed significantly to the understanding of radioactive elements. The Curies' discovery of polonium and radium, as well as further investigations into the properties of radioactive substances, were particularly groundbreaking and led to Marie Curie being awarded the Nobel Prize in both Physics and Chemistry. This level of recognition highlights the competitive nature of her work, as well as the profound impact she had on the field of radioactivity.