Question

In the field of chemistry, the number of elements that have been discovered since 1871 is:

A) Less than 50
B) Approximately 100
C) Over 150
D) Exactly 118

Which of the following pairs of elements in the periodic table exhibit atomic masses in the opposite order to their atomic numbers?
A) Hydrogen and Helium
B) Carbon and Oxygen
C) Sodium and Magnesium
D) Chlorine and Argon

In the realm of science, how many elements have been named after planets and other heavenly bodies in the universe?
A) Five
B) Seven
C) Ten
D) Thirteen

Answer 1

Since the establishment of the periodic table by Dmitri Mendeleyev, scientists have discovered new elements, bringing the total count to 118, including about 28 synthetic ones. These discoveries have continued over the years with 13 elements found from 1900 to 1949 and recent confirmations of new elements by IUPAC.

Step-by-step explanation:

The subject of this question is Chemistry, which involves the study of the elements, compounds, and the reactions between them. Since Dmitri Mendeleyev's formulation of the periodic table in 1870, there have been a significant number of new elements discovered. By the late 19th century, scientists had identified nearly 70 elements, and as of the latest updates to the periodic table, there are 118 recognized elements.

While there are approximately 90 naturally occurring elements on Earth, advancements in technology have enabled chemists to create about 28 synthetic elements. Some of these discoveries occurred in different periods, including the period from 1900 to 1949 when 13 new elements were discovered, often with the help of developments in quantum theory and mechanics.

More recently, the International Union of Pure and Applied Chemistry (IUPAC) confirmed the discovery of new elements, such as elements 113, 115, 117, and 118, further expanding our understanding of chemical substances. These synthetic elements, however, are typically very unstable and exist for a very short period of time.