Question

What is meant by man-made elements?

Answer 1

Hint: An element is a species of atoms with the same number of protons and electrons present in the atomic nucleus. There are two types of elements that exist on earth these are: (a) Naturally occurring elements and (b) Man-made elements.

Complete answer:
The Chemical elements were first presented by the English scientist named Robert Boyle. According to his definition, an element is a substance that is incapable of decomposition, and being a true scientist he predicted that accurately.
There is a hypothesis that originally chemical elements were produced by a process of evolution from much simpler forms of matter indicated by the progressive chemical complexity observed by passing through hot stars to cold planets.
Man-made elements or synthetic elements are the elements that do not occur naturally but are synthesised in the laboratory. There are $24$ man-made elements that were synthesized in the laboratory. They are unstable and radioactive in nature.
The mechanism that is used in the creation of a synthetic element is to inject additional protons on the nucleus of an element whose atomic number is lower than 95. All synthetic elements that are synthesised are unstable, but their decaying rate is very wide.
Atoms of the synthetic elements which exist on Earth are formed from atomic bombs or experiments that involve nuclear reactors or particle accelerators through nuclear fusion or neutron absorption.
Examples of synthetic elements are technetium, promethium, neptunium, plutonium, americium, curium, berkelium, etc.

Note:
The first element which was synthesised in the laboratory, instead of being discovered in nature, was technetium in $1937$. This discovery of technetium filled the gap in the periodic table, and the fact that there are no stable isotopes of technetium exists explains its natural absence on earth.