An (1)______ is a substance that cannot be broken down into simpler substances by any(2) _____ process. (3)_____ are considered as the building blocks of matter. Elements could either have (4)_____ and _(5)____ properties. _(6)_____ properties can be readily observed by the human sense while _(7)_____ properties can be observed when the __(8)__ is changed. Examples of physical properties are _(9)____, ____(10)__, ___(11)__, __(12)__, and _(13)__ while for chemical properties are __(14)__, _(15)___, ___(16)_, __(17)__, and _(18)__.
An element is the simplest form of matter that has a unique set of properties. Examples of well-known elements include oxygen, iron, and gold (see the figure below). Elements cannot be broken down into a simpler substance. Likewise, one element cannot be chemically converted into a different element.
