Category Nuances for null:

• suspended,
• pure,
• free,
• biogenic,
• inert,
• inorganic,
• dry,
• frozen,
• dilute,
• key,
• transparent,
• simple,
• atomic,
• heated,
• respiratory,
• mental,
• out,
• diatomic,
• valuable,
• extraneous,
• corrosive,
• atmospheric,
• incombustible,
• elemental,
• controlled,
• diffusing,
• poisonous,
• expensive,
• larger,
• electronegative,
• safe,
• industrial,
• anthropogenic,
• combustible,
• individual,
• deleterious,
• side,
• minor,
• familiar,
• natural,
• nitrogenous,
• essential,
• dense,
• neutral,
• smaller,
• invisible,
• raw,
• important,
• cheap,
• vital,
• scientific,
• inflammable,
• third,
• lighter,
• suitable,
• hot,
• clean,
• charged,
• intermediate,
• technical,
• harmless,
• stimulating,
• beneficial,
• cold,
• volatile,
• desirable,
• isotopic,
• medium,
• standard,
• undesirable,
• large,
• structural,
• noncombustible,
• convenient,
• warm,
• toxic,
• main,
• heterogeneous,
• medical,
• relevant,
• conductive,
• dangerous,
• basic,
• medicinal,
• small,
• nonflammable,
• conventional,
• protective,
• edible,
• working,
• inexpensive,
• major,
• inanimate,
• particulate,
• polar,
• nutrient,
• auxiliary,
• base,
• mobile,
• nonpolar,
• organic,
• consumable,
• skeletal,
• cultural,
• useful,
• acidic,
• abundant,
• critical,
• liquified,
• unhealthy,
• biodegradable,
• fixed,
• electropositive,
• nonmetallic,
• mixed,
• external,
• monatomic,
• available,
• central,
• rich,
• model,
• ordinary,
• liquefied,
• active,
• refrigerated,
• numerous,
• propellant,
• impure,
• nutritious,
• hazardous,
• gaseous,
• covalent,
• heavier,
• flammable,
• nutritional,
• polyvalent,
• soluble,
• stable,
• noble,
• interfering,
• insoluble,
• cheaper,
• permanent,
• compressed,
• refrigerant,
• single,
• renewable,
• biochemical,
• residual,
• supercritical,
• light,
• functional,
• chemical,
• reactive,
• rare,
• heavy,
• real,
• foreign,
• saturated,
• thin,
• pathogenic,
• heterocyclic,
• gross,
• noxious,
• metalloid,
• common,
• significant,
• cryogenic,
• supplemental,
• radioactive,
• special,
• environmental,
• dietary,
• unwanted,
• benign,
• compressible,
• innocuous,
• monoatomic,
• diamagnetic,
• explosive,
• molecular,
• solid,
• elastic,
• number,
• dissolved,
• solar,
• ambient,
• complex,
• hydrophilic,
• nontoxic,
• particular,
• harmful,
• nutritive,
• liquid,
• passive,
• biological,
• unconventional,

Simple Categories for null:

• gas,
• control,
• atom,
• fumes,
• oxygen,
• quantity,
• nonmetal,
• atmosphere,
• object,
• system,
• attribute,
• fluid,
• material,
• volatile,
• solute,
• unit,
• component,
• measure,
• substance,
• amount,
• solid,
• hydrogen,
• matter,
• constituent,
• air,
• stuff,
• group,
• metal,
• entity,
• affinity,
• element,
• liquid,
• substrate,
• change,
• mixture,