oxygen
chemical reactions
Roentgenium is an artificial element, obtained via nuclear reactions in particle accelerators.
The answer is oxygen
An element is made up of only one kind of atom and cannot be broken down by chemical reactions. Each element is defined by the number of protons in its nucleus, which determines its unique properties.
During chemical reactions atoms remain unchanged.
oxidation or reduction of an element
There are three main types of single‐replacement reactions: metal‐displacement reactions, halogen‐displacement reactions, and nonmetal‐displacement reactions. Each type involves the substitution of one element in a compound by another element.
oxygen
Nobelium is an artificial element; it is prepared only by nuclear reactions in accelerators.
A Decomposition Reaction, Single Replacement Reactions, Double Replacement Reactions and Combustion Reactions...
Enzyme
yes
chemical reactions
Combustion reactions cannot involve a free element as a reactant since they involve the reaction of a fuel-rich substance with an oxidizing agent to produce heat and usually carbon dioxide and water. Two nonmetals combining to form a covalent bond also cannot involve a free element as a reactant.
Roentgenium is an artificial element, obtained via nuclear reactions in particle accelerators.
For example, water reacts with zinc, releasing hydrogen, an element.