CHEMISTRY SEPTEMBER 17, 2014 Matter

SCIENCE STARTER Work on Science starter You have 3 minutes This is silent and individual work

OBJECTIVES SWBAT – Identify the Phases (States) of Matters – Identify the different change in state of matters

AGENDA Science Starter Discuss the states of matter Identify the different change in state of matters Worksheet

Lab First Lab is tomorrow Safety Lab Located here in this room

PHASES (STATES) OF MATTER

PHASES OF MATTER How many phases of matter?

SOLID fixed volume and shape that result from the way their particles are arranged held together through their attractive forces that are between particles particles are held tightly in a rigid structure they vibrate only slightly symbolically can be shown as NH 3 (s), where (s) = solid

2 CLASSES OF SOLID – crystalline = can be very hard and brittle (e.g., salt, diamond, sugar) and arranged in a regular geometric pattern – amorphous = soft (randomly arranged in three dimension = no definite shape) (e.g. lead, plastic, rubber)

Examples

LIQUID fixed volume BUT no fixed shape held together through their attractive forces that are between particles particles are held not as tightly as solid can flow and take the shape of the container symbolically can be shown as NH 3 (l), where (l) = liquid

LIQUID (CONT’) particles slip past one another, thus liquid is fluid – some can flow readily (such as water or gasoline) – some are thicker and more viscous so flow slowly (e.g., molasses) viscous = a measure of its resistance to gradual deformation by shear stress or tensile stress

COHESION AND ADHESION Liquid can have cohesion (attraction for each other) and adhesion (attraction for particles of solid surfaces – the balance of the cohesion and adhesion force determines if the liquid will wet the solid surface

CAR WAX EXAMPLE e.g., water drops have a high cohesion to one another and low adhesion to car wax. So water drops tend to stick together rather than stick to the car wax

SURFACE TENSION – Liquid can have surface tension (the force that acts on the surface of a liquid and that tends to minimize the area of the surface) thus, liquid tends to be spherical shapes since a sphere has the smallest surface area for a given volume

Example

GAS No fixed volume. No fixed shape Particles are weakly attracted to one another and move independently at high speed Will fill up any container that they occupy as their particles move apart

GAS (CONT’) Shape, volume and density depend upon the shape and size of the container Is fluid since it can move around freely symbolically can be shown as NH 3 (g), where (g) = gas

Example

3 STATES OF MATTER

CHANGE IN STATE OF MATTER

CHANGES IN STATE OF MATTER Freezing Melting Evaporation Condensation Sublimation Deposition

State of Matter Worksheet Do worksheet Read the Aim 6