An "element"
Elements cannot be changed into simpler substances by chemical means. To change them into simpler particles, you need nuclear means.
An element.
physical means only
The substance is a compound, which forms chemical bonds that cannot be physically separated, but only by a chemical change.
element, compound, or an atom
cannot be broken down into simpler substances by chemical means
An element.
studyisland answer : water
An element cannot be separated into simpler substances by chemical means.
An element cannot be broken down into a simpler substance by chemical means.
A substance that can not be decomposed into simpler substance by a chemical or physical means is a chemical element.
A substance composed of atoms having an identical number of protons in each nucleus. Elements cannot be reduced to simpler substances by normal chemical means.