One grain of sand is a single molecule of silicon dioxide (made of of the atoms Silicon and Oxygen). The reason for its large size (relatively speaking) is because of its giant covalent structure - the same structure that is found in diamond.
A substance made up of only one kind of atom is an element, which is a pure substance.
Elements
They are elements.
Elements
An element.
a regular atom
Yes.
Element
an element
an element or a molecule
An element is made up of one kind of atoms
Atom are made up of Protons, electrons and neutrons.Atoms combine together by chemical bonding to form a particular molecule. for example, one carbon and four hydrogen atoms combines to forms methane (CH4)