Read the passage below carefully, and then choose the best answer:
The Invention of the Periodic Table
If you are looking to gain a better understanding of the world around you, chemistry is the perfect subject to study. It is an examination of matter, its properties, and its interactions with everything around it. Where physics often deals with concepts and theories that are difficult to test and observe, chemistry principles can easily be applied to medicine, cooking, and several other areas. At the heart of all these discoveries is one vital chart that organizes elements based on their atomic number and chemical properties: the periodic table. Although the first periodic table was published in 1869, it was a work in progress for hundreds, if not thousands of years. Since ancient times, people have been fascinated with elements such as gold, tin, and copper in their natural forms. They were mined and used to make jewellery, weapons, coins, and many other things. Over time, people became more curious about these metals and how they were composed. In ancient Greece, Aristotle and other philosophers claimed things were made from the elements of earth, water, fire, and air. For years, this theory was accepted. Then people began to reevaluate this concept during the Age of Enlightenment. In 1661, Irish scientist Robert Boyle defined an element as something that “cannot be broken down into a simpler substance by a chemical reaction”. Over a century later, French chemist Antoine-Laurent Lavoisier would publish the first modern textbook on chemistry. In it, he listed several substances which he believed should be classified as elements into two categories: metals, and non-metals. Although his work wasn’t completely accurate, it represented a major step forward at the time. Over the next century, scientists started to classify the elements into different groups depending on their properties and atomic weights. However, it is Russian chemist Dmitri Mendeleev who is usually credited as the first person to make a periodic table. Although other scientists had submitted tables, they were eventually rejected by the scientific community for a lack of detail. Mendeleev arranged all of the elements according to their atomic mass. He was even smart enough to leave empty spaces for elements which hadn’t been discovered at the time. Although Mendeleev’s periodic table wasn’t perfect, it set the format which is similar to the one used today.
6. Why is Mendeleev usually given credit for inventing the periodic table?
