ChemIONS

how do you know if something is a macromolecule? for instance, tin (IV) chloride is a covalent substance. why is it not a macromolecule? and for group IV elements, since they are a mix of metals and non-metals, how do you know if they will form ionic or covalent compounds?

Wiki defines a macromolecule as The term macromolecule by definition implies "large molecule". In the context of biochemistry, the term may be applied to the four conventional biopolymers (nucleotides, proteins, carbohydrates, and lipids), as well as non-polymeric molecules with large molecular mass such as macrocycles. That's a good definition. To determine if a compound has ionic, polar covalent of colvalent bond, you need to know the electronegativity values for the atoms in the bond. Simply subtract the highest from the lowest. Sources differ slightly on the exact range values; however, a general rule of thumb is: 0.0 - 0.4 = covalent 0.41 - 1.8 = polar covalent 1.8+ = ionic

is there a simpler way to differentiate between simple covalent substances and macromolecules? o_o

The most common factor that separates a macromolecule from a covalent compound is that a macromolecule is generally a polymer - it is made from monomers, smaller and often repeating compounds. For example, ethene is H2C=CH2. This simple molecule can form a chain H2C=(C)x=CH2, this is called polyethylene. Another example are proteins which are composed from amino acids. If you want an even simpler (but less accurate) means of separating macromolecules for covalent compounds, try using the 100 Rule. It states that if a substance is composed of more than 100 atoms then it is a macromolecule.