Science AHSGE Standard II Objective 2- States of Matter

Matter Anything that has mass and takes up space States of Matter: Kinetic Molecular Theory: Matter is made of atoms which are in constant motion Temperature- Average movement of particles (kinetic energy) Change in temperature (motion of particles) = change in state of matter States of Matter: Solids Liquids Gases Plasma

Plasma 99% of known matter in universe- stars and other planets No definite shape; particles broken apart Ionized gas Appears to be solid Conducts electricity Affected by magnetic and electric fields

Solids Definite shape; does not take shape of container Definite volume; always same amount of space Atoms tightly packed together in rows Vibrate slowly back and forth in place Lowest kinetic energy

Characteristics of Solid Malleability- Ability to be hammered into thin sheets Ex: Gold flattened into jewelry Elasticity- Ability to stretch and return to original position Ex: Rubberband Brittleness- Ease with which it breaks Ex: Glass is more brittle than steel Hardness- Ability to resist scratching Ex: Diamond is harder than soap Tensile strength- Resistance to breaking under pressure Concrete withstands hitting while paper may tear

Liquids Definite volume No definite shape; takes shape of container Molecules loosely packed together Particles able to slide past one another More kinetic energy than solids

Density and Floating Density = mass (g) Volume (ml) Solids tend to be more dense than liquids of the same substance; liquids more than gas In order for an object to float, its density must be less than the liquid it is in Example: Density of water = 1 g/ml 0.34 g/ml stick floats 2 g/ml stick sinks

Characteristics of Liquids Viscosity- Resistance of a liquid to flow (thickness) Syrup is more viscous than water Surface tension- Tendency to form a skin on the surface when sitting still Ponds develop and water bugs jump on Cohesion- Particles of the same substance sticking together Water molecules stick together to flow Adhesion- Particles of different substances sticking together Water molecules sticking to sides of glass graduated cylinder forming a meniscus

Gases No definite volume; completely fills all space available No definite shape; takes entire shape of closed container Particles repel each other; very far apart Most kinetic energy; fast movement Expands (increase in volume) when heated & vice versa