Answer:
- Molecule:
A group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
- Compound:
Chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.
- Element:
An element is a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nuclei.
- Mixture:
Is a material made up of two or more different Chemical substance/substances which are not chemically combined.
- Heterogeneous:
Generally means consisting of different, distinguishable parts or elements.
- Homogeneous:
A mixture in which the composition is uniform throughout the mixture.
- Atom:
The smallest unit of ordinary matter that forms a chemical element.
- Valence Electrons:
Are the electrons in the outermost shell, or energy level, of an atom.
- Covalent atoms:
A covalent bond forms when two non-metal atoms share a pair of electrons.
- Ionic atoms:
Is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds.