.... is the no.of atoms of an element that join together farming a molecule of that element
Answers
Explanation:
determined by their structures. The simplest structural unit of an element is an atom. Atoms are very small. A hundred million (100,000,000) hydrogen atoms put side-by-side is only as long as one centimeter!

Fig. 2.8. Elements can be made of one atom, like He, or be elemental molecules, such as hydrogen (H2), oxygen (O2), chlorine (Cl2), ozone (O3), and sulfur (S8). Atoms are not drawn to scale.
Image by Bryon Inuoye
Some elements are monatomic, meaning they are made of a single (mon-) atom (-atomic) in their molecular form. Helium (He, see Fig. 2.8) is an example of a monatomic element. Other elements contain two or more atoms in their molecular form (Fig. 2.8). Hydrogen (H2), oxygen (O2), and chlorine (Cl2) molecules, for example, each contains two atoms. Another form of oxygen, ozone (O3), has three atoms, and sulfur (S8) has eight atoms. All elemental molecules are made of atoms of a single element.

Fig. 2.9. Compounds are made of two or more atoms of different elements, such as water (H2O) and