The new substance formed when elements combine chemically is called a compound.

Here's why:

* Elements are the simplest pure substances. They cannot be broken down into simpler substances by chemical means. Examples include oxygen (O), carbon (C), and hydrogen (H).

* Compounds are formed when two or more different elements combine chemically in a fixed ratio. This means the elements are held together by chemical bonds, resulting in a new substance with properties distinct from its constituent elements. Examples include water (H₂O), carbon dioxide (CO₂), and table salt (NaCl).

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