Physical Quantities

Mass

Quantity of matter contained in a substance; constant regardless of location; SI unit kilogram.

Weight

Force exerted on a body by gravity; varies with distance from Earth's center; measured in Newtons.

Balance

Instrument used to determine mass by comparing against known standards.

Triple Beam Balance

Weighing device with three sliding masses; sensitivity 0.01 g; moderate precision.

Top Loading Balance

Electronic balance; sensitivity 0.01 g to 0.0001 g; higher precision.

Spring Balance

Device that measures weight directly by gravitational stretch; units in Newtons.

Length

Distance between two points; SI unit meter.

Ruler

Straightedge marked in millimeters/centimeters or inches; sensitivity 0.01 cm.

Vernier Caliper

Precision instrument measuring internal/external diameter and length; sensitivity 0.005 cm or 0.001 cm.

Micrometer Caliper

Screw-gauge instrument for fine dimensions; sensitivity 0.001 mm.

Volume

Space occupied by matter; SI unit cubic meter; common units liter and milliliter.

Meniscus

Curved liquid surface; graduated cylinder readings taken at bottom of lower meniscus.

Water Displacement

Method determining irregular object volume by measuring liquid-level rise upon submersion.

Density (ρ)

Mass per unit volume; characteristic property of substances; units g/mL, g/cm³, or kg/m³.

Specific Gravity

Ratio of a substance's density to a reference density (water for liquids/solids, air for gases); unitless.

Temperature

Measure of relative hotness or coldness; measured by thermometer.

Celsius Scale (Anders Celsius)

Temperature scale where water freezes at 0°C and boils at 100°C.

Fahrenheit Scale (Daniel Gabriel Fahrenheit)

Temperature scale where water freezes at 32°F and boils at 212°F.

Kelvin Scale (Lord Kelvin)

Absolute temperature scale; zero at absolute zero; water freezes at 273 K, boils at 373 K.