Chapter 2: MATTER

The Particle model of matter

All substances are forms of matter Occupies space and has mass Physical Science 2.1 p. 21 Describing Matter All substances are forms of matter Occupies space and has mass Can be sensed and measured Can exist as immense objects or subatomic particles

What forms of matter and nonmatter can you see in this room? Physical science 2.1 p. 21 Figure 2-2 What forms of matter and nonmatter can you see in this room?

b. subdivided infinitely c. no smallest particle Physical Science 2.2 p. 22-24 The Particle Model Two main concepts Matter is continuous a. Aristotle b. subdivided infinitely c. no smallest particle

2. Matter is not continuous a. many of the Greek philosophers Physical Science 2.2 p. 22-24 The Particle Model Two main concepts 1. Matter is continuous 2. Matter is not continuous a. many of the Greek philosophers b. subdividing must eventually stop at a smallest particle

The Debate in Ancient Times Physical Science 2.2 pp. 22-24 The Debate in Ancient Times 1600’s: Particle Theory of Matter begins to emerge Mid-1800’s: PT generally accepted by scientists

Particle Theory of Matter Physical Science 2.2 pp. 22-24 Particle Theory of Matter Diameter of typical particles measured in nanometers Different kinds of particles most common particle scientists refer to is the atom

Physical Science 2.2 pp. 22-24 The Particle Model The properties of matter that we can sense or measure are due to the way the uncountable particles work together in the substance

Evidence for the Particle Model Physical Science 2.3 pp. 25-26 Evidence for the Particle Model Particle model of matters assumes It is made up of tiny particles (atoms or molecules) Particles are in constant motion

Brownian motion in action Physical science 2.3 pp. 25-26 Brownian motion in action Dissolving sugar into tea Dissolving crystal light mix into water Potassium permanganate in water

Physical science 2.3 pp. 25-26

Kinetic-molecular theory Physical science 2.3 pp. 25-26 The Particle Model Kinetic-molecular theory Another name scientists used Kinetic refers to motion

Physical science 2.3 pp. 25-26

Contains protons, electrons, and usually neutrons Physical Science 2.4 p. 26 The Atom Contains protons, electrons, and usually neutrons Center of the atom is the nucleus Contains one or more protons and may or may not have neutrons Electrons are orbitting the nucleus

Physical Science 2.4 p. 26

Protons – positive charge Neutrons – neutral charge Physical scienc 2.4 p. 26 Protons – positive charge Neutrons – neutral charge Proton mass = neutron mass Electrons – negative charge Electron mass is negligible

All matter has mass and takes up space Nucleus determines mass Physical science 2.3 p. 2 All matter has mass and takes up space Nucleus determines mass Electron cloud determines volume

Two or more atoms chemically bonded together Physical Science 2.5 p. 26 The Molecule A distinct particle Two or more atoms chemically bonded together Usually neutral in their charge

Particles with unbalanced electrical charges Physical Science 2.6 p. 27 Ions Particles with unbalanced electrical charges Formed by atoms gain or lose electrons Form important and common forms of matter like rocks and salts

Question What is “mixing” due to particle motion? Diffusion Boiling Freezing Melting Question

T/F A molecule consists of atoms chemically bonded together. Question