Simple categories matching elementary:

• polygon,
• relationship,
• object,
• product,
• particle,
• action,
• state,
• system,
• entity,
• automaton,
• shape,
• sign,
• piece,
• representation,
• antiparticle,
• unit,
• information,
• notion,
• transformation,
• principle,
• force,
• figure,
• attribute,
• activity,
• stream,
• characteristic,
• form,
• stage,
• process,
• aspect,
• faculty,
• motion,
• case,
• phenomenon,
• signal,
• idea,
• lepton,
• reaction,
• calculation,
• theme,
• topic,
• quantity,
• carbon,
• constituent,
• volume,
• training,
• feature,
• semiconductor,
• concept,
• organism,
• set,
• class,
• metal,
• algebra,
• part,
• perception,
• function,
• flow,
• facility,
• instrument,
• emotion,
• pattern,
• evidence,
• modality,
• spread,
• operation,
• item,
• measurement,
• symbol,
• article,
• tool,
• circuit,
• picture,
• vocabulary,
• mechanism,
• thing,
• task,
• measure,
• group,
• operations,
• way,
• equipment,
• essential,
• instruction,
• structure,
• operator,
• defect,
• organization,
• analysis,
• material,
• surface,
• block,
• program,
• knowledge,
• subject,
• event,
• behavior,
• ability,
• substance,
• behaviour,
• necessity,
• property,
• sensation,
• movement,
• component,
• antenna,
• curve,
• wave,
• type,
• source,
• statistics,
• fragment,
• solid,
• gates,
• mathematics,

Members with property elementary:

• physical_association,
• electron,
• proton,
• chemical_structure,
• wimp_neutrino,
• capacity,
• binocular_disparity,
• audio_clip,
• sight,
• hadron,
• letters,
• photon,
• quark,
• neutron,
• electronic_gates,
• weight,
• line,
• general_characteristic,
• hydride_decomposition,
• straight_line,
• parallelepiped,
• click_behavior,
• molecule,
• power_function,
• thin_layer,
• philosophy,
• circle,
• arithmetic,
• timer,
• repetitive_exercise,
• flow,
• atom,
• toothpick,
• activation,
• connectedness,
• bit_flip,
• passage,
• absorption,
• hammer,
• powder,
• response_facilitation,
• triangle,
• growth,
• differential_circuit,
• motion_detection,
• earth,
• battery,
• inhibitory_control,
• chance,
• gear,
• hyperon,
• circular_disk,
• testing,
• boundedness,
• margin,
• button,
• vertex,
• interoperability,
• vessel,
• plant,
• elongated_elements,
• words,
• valve,
• gas,
• repetition,
• direct_wave,
• tellurium,
• plane_wave,
• heat_capacity,
• speed,
• wimp,
• rectangle_parallelogram,
• ellipsoid,
• pion,
• alphabet,
• sine_function,
• strand,
• mass,
• fiber,
• computer,
• channel,
• outward_deal,
• crop_report,
• trigonometric_function,
• dynamics,
• lightning,
• classroom,
• tetrahedron,
• comparison,
• deposition,
• power,
• detachment,
• music,
• pin,
• symmetry,
• spiral,
• loop,
• generic,
• room,
• amide,
• roof,
• natural_exponential,
• fastener,
• aluminum,
• temperature_sense,
• isolation,
• tree,
• bearing,
• dissociation,
• spread,
• integer,
• variable,
• shovel,
• constant,
• banjo_part,
• number,
• feature,
• nontransferable_frame,
• reaction,
• emission,
• auger_decay,
• quadratic,
• organelle_activity,
• oval,
• index,
• polymerase_binding,
• step_ionization,
• observation_operator,
• fill,
• square-root_function,
• memory_circuit,
• entablature,
• memory,
• lepton,
• arc,
• jewish_history,
• sigma_particle,
• material,
• molecular_weight,
• simple_attention,
• membrane,
• inflection_point,
• superstring,
• bond,
• capture,
• logical_condition,
• analytic_geometry,
• abstraction,
• muon,
• arctan,
• heat,
• understanding,
• proton_neutron,
• value_domain,
• hoe,
• pipe,
• windscreen,
• data_type,
• individual_word,
• molybdenum,
• sin,
• animal,
• formula_unit,
• nature_play,
• point,
• enterprise,
• alphanumeric_character,
• reactor,
• calculation,
• college_algebra,
• measure,
• transformation,
• polycrystalline_silicon,
• grasping,
• continuity,
• minute_particle,
• early_perception,
• calculation_formula,
• release,
• hot_water,
• wave,
• inductor,
• video,
• folic-acid_supplementation,
• robot,
• reflective_surface,
• area,
• rotation,
• linear_algebra,
• ruler,
• punctual_sensation,
• bicycle,
• brightness,
• sex_behaviour,
• disc,
• brick,
• differentiation,
• chromosome,
• bright_colors,
• rent_commitment,
• quadrangle,
• type,
• respiration,
• chain_motion,
• plan,
• bricklaying,
• paper,
• video_stream,
• ellipse,
• diffusion,
• motor_activation,
• resistor,
• note,
• chemical_transformation,
• expansion,
• wave_height,
• sort,
• exponential,
• fermion,
• phase_margin,
• size,
• perimeter,
• radical,
• form,
• assumption,
• distillation,
• boson,
• helix,
• hate,
• elementary_algebra,
• hole,
• transistor,
• hemisphere,
• bull_spread,
• activity_room,
• tutorial_form,
• soliton_generation,
• vehicle,
• memory_requirement,
• history,
• organizational_preparation,
• rectangle,
• smoke,
• dna_molecule,
• surface,
• proper_utensil,
• working_memory,
• free_vortex,
• volume,
• attachment,
• edge,
• relations,
• simulation,
• average,
• paved_roads,
• quarter_circle,
• fraction,
• rotation_group,
• density,
• elementary_calculus,
• muscle,
• cube,
• streak,
• chamber,
• lumber,
• continuous_line,
• tangent,
• private_stream,
• heat_transfer,
• shape,
• flash_unit,
• image_gates,
• distance,
• prism,
• direct_effectiveness,
• kaon,
• darkness,
• point_vortex,
• electrostatic_potential,
• feed,
• ion,
• given_rotation,
• tan,
• hyperbolic_function,
• multiplying_matrix,
• protein_transport,
• aquatic_product,
• filter,
• electric_charge,
• smooth_cylinder,
• light_wave,
• toilet,
• droplet_deposit,
• grain,
• composition,
• geographical_distribution,
• direct_dissociation,
• clean_water,
• cosine,
• temperature,
• spatial_relations,
• recording_conversation,
• divider,
• attention,
• coordination,
• pressure,
• spring_picture,
• silicon,
• bathroom,
• software,
• germanium,
• wheelbarrow,
• graphics,
• test_signal,
• clock_generator,
• cell,
• grapheme,
• stroke,
• execution_time,
• compass,
• move,
• point_barycenter,
• trapezoid,
• aaa_program,
• shot,
• inverter_gates,
• love,
• vibratory_sensation,
• electron_capture,
• door,
• single_fiber,
• cuboid,
• rarefaction_wave,
• accidental,
• bone,
• addition,
• slider,
• cellular_rhythm,
• truss,
• semicolon,
• adder,
• location,
• position_sense,
• apoptosis,
• cold,
• acidity,
• pick,
• parcel,
• graviton,
• soil_ph,
• cylinder,
• centroid,
• gas_diffusion,
• ip_address,
• precipitation,
• ladder_structure,
• bi,
• lifting_steps,
• color,
• practice,
• inference,
• gravity,
• square,
• polynomial,
• data_elements,
• touch,
• sensation,
• number_theory,
• significance,
• waveguide,
• cultural_amenities,
• electron_mass,
• nucleus_growth,
• neutrino,
• ph,
• anaphora_resolution,
• straightedge,
• chain_stage,
• chicken,
• detector_click,
• image,
• co2_fixation,
• footer,
• development,
• clock_setting,
• polyhedron,
• eyes,
• jawan_name,
• planar_face,
• values,
• mobility,
• unambiguity,
• electron_charge,
• regular_polygon,
• candle,
• beam,
• eye,
• water,
• eyes_nose,
• unit_steps,
• metadata_stream,
• label,
• plane,
• wood,
• sphere,
• box,
• contrast,
• algebra,
• simple_touch,
• joke,
• thread_state,
• algorithm,
• exponential_set,
• real_number,
• disk,
• comma,
• subtraction,
• fire,
• place_value,
• desorption,
• pain,
• theory,
• translation,
• surface_texture,
• attaching_part,
• division,
• trigonometry,
• ionization,
• news_release,
• nuclear_reaction,
• buffer,
• spline,
• needle,
• blade,
• motion,
• corollary_delivery,
• rest,
• audio,
• parabola,
• table_manners,
• point_centroid,
• perceptual_threshold,
• program,
• screw,
• bromine_abstraction,
• gymnasium,
• kitchen,
• electron_neutron,
• horizontal_line,
• road,
• orthogonal_polynomial,
• ester,
• oxidative_addition,
• phrase-structure_rule,
• germicidal_lamp,
• tissue,
• decomposition,
• charge_transfer,
• character,
• filtration,
• antiproton,
• nucleus_formation,
• fear,
• uniform_flow,
• spherical_wave,
• gates,
• perception,
• basic_geometry,
• discriminating_quantity,
• basic_dome,
• bunting_material,
• parallelogram,
• massive_neutrino,
• spring,
• multiplication,
• polygon,
• biochemical_transformation,
• crystal_structure,
• space,
• preparation,
• nonagon,
• syntax,
• soil,
• concept,
• bounding_rectangle,
• plate_source,
• sealing_system,
• fork,
• unstable_resonator,
• low_education,
• ax_position,
• frame,
• point_defect,
• single_photon,
• cos,
• chin,
• active_filter,
• crystal_silicon,
• event,
• harmonic_oscillator,
• descriptive_biology,
• chromium,
• vein,
• audio_stream,
• screwdriver,
• teeth,
• semiotic_square,
• chemisorption,
• room_dimension,
• cone,
• feature_extraction,
• orientation,
• camera,
• small_line,
• reactant_coordination,
• people,
• antimatter_particle,
• employee_orientation,
• site_transformation,
• dipole,
• nail,
• ellipsis,
• variable_assignment,
• correlation,
• empty_aluminum,
• taste,
• arctangent,
• adequate_kitchen,
• variable_access,
• ion_generation,
• logarithmic_function,
• generalized_cylinder,
• block,
• drawing,
• photosynthesis,
• use,
• texture,
• association,
• nose,
• movie_frame,
• ratchet,
• fact,
• header,
• building,
• contact,
• file,
• pump,
• disposable_needle,
• compactness,
• table,
• clock_tick,
• radio,
• function,
• cartilage,
• adsorption,
• variable_type,
• graphics_stream,
• navigation,
• place,
• kinship,
• rank-order_case,
• differential_form,
• fabric,
• dot,
• meson,
• interval,
• counter,
• washing,
• deep_pressure,
• mouse_move,
• reductive_elimination,
• descriptive_statistics,
• si,
• positron,
• wedge_product,
• mouth,
• system_stream,
• electron_transfer,
• gas_temperature,
• gain,
• fae,
• integrator,
• graphite,
• string,
• text,
• mass_transfer,
• model_comparison,
• stick,
• bolt,
• ease,
• mass_spectrometry,
• ge,
• average_benefit,
• particle,
• combustion_reaction,
• involute_curve,
• amorphous_silicon,
• batch_exposure,
• euclidean_group,
• colors,
• text_body,
• uv_spectroscopy,
• main_gas,
• rate_laws,
• light,
• spark,
• vortex,
• golden_rectangle,
• replication_slippage,
• honor_roll,
• school_address,
• resonant_dissociation,
• charge,
• wedge,
• minimum,
• fibre,
• harmonic_interval,
• uniqueness,
• capacitor,
• sound_source,
• curve,
• gauge_particle,
• gluon,
• network_connection,
• diamond,
• boundary,
• column,
• ionic_current,
• transport,
• hydrogen_abstraction,
• nutrition,
• vocal_gesture,
• charcoal,
• air,
• geography,
• surface_diffusion,
• replacement,
• plank,
• geometry,
• conic,
• lense,
• adjectival_agreement,
• morpheme,
• ge_germanium,
• line_source,
• si_silicon,
• depth,
• macromolecule,
• four_rule,
• value,
• error_function,
• vector_model,
• sine,
• pencil,
• alarm_collector,