CHAPTER 2 MATTER THE PARTICLE MODEL OF MATTER

CHAPTER 2: MATTER

THE PARTICLE MODEL OF MATTER

PHYSICAL SCIENCE 2. 1 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 p. 21

PHYSICAL SCIENCE 2. 1 p. 21 Figure 2 -2 • What forms of matter and nonmatter can you see in this room?

PHYSICAL SCIENCE 2. 2 The Particle Model • Two main concepts 1. Matter is continuous a. Aristotle b. subdivided infinitely c. no smallest particle p. 22 -24

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

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

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

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

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

PHYSICAL SCIENCE 2. 3 The Particle Model • Kinetic-molecular theory • Another name scientists used Kinetic refers to motion pp. 25 -26

PHYSICAL SCIENCE 2. 3 pp. 25 -26

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

PHYSICAL SCIENC 2. 4 • Protons – positive charge • Neutrons – neutral charge • Proton mass = neutron mass • Electrons – negative charge • Electron mass is negligible p. 26

PHYSICAL SCIENCE 2. 3 p. 2 • All matter has mass and takes up space • Nucleus determines mass • Electron cloud determines volume

PHYSICAL SCIENCE 2. 5 The Molecule • A distinct particle • Two or more atoms chemically bonded together • Usually neutral in their charge p. 26

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

What is “mixing” due to particle motion? 1. 2. 3. 4. Diffusion Boiling Freezing Melting Question

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