scientist
The Spanish word 'científico' translates into English as 'scientist'. A 'científico' is a professional engaged in systematic activity to acquire knowledge that describes and predicts the natural world. In a more specialized context, a 'científico' can be a person who is an expert in a specific field of science, for example, a physical scientist, a social scientist, a biological scientist, and so forth.
The scientist is conducting an experiment in the laboratory.
This sentence uses the term 'científico' to describe a professional person who is conducting an experiment in a laboratory. This sentence is in present tense, denoting that the action is happening in the present time.
The work of a scientist is important for the development of humanity.
In this sentence, 'científico' is used to refer to the general career or job of a scientist. It discusses the importance of a scientist's work for human development, presenting a general opinion.
The book written by the famous scientist sold quickly.
This sentence uses 'científico' to describe the author of a book. The author is not only a scientist but also a famous one, and the book they wrote was sold quickly. This sentence is in past tense.