Chapter+2+Review.pdf

Matter Chapter 2 Summary • Matter • Anything that has mass and takes up space • Mass is the amount of matter in an object • Volume is the space matters takes up • Density is mass divided by volume m d= V m =dV m V= d Chapter 2 Summary Particle model of matter leads to the idea of atoms • Brow...

Matter Chapter 2 Summary • Matter • Anything that has mass and takes up space • Mass is the amount of matter in an object • Volume is the space matters takes up • Density is mass divided by volume m d= V m =dV m V= d Chapter 2 Summary Particle model of matter leads to the idea of atoms • Brownian motion—random movement of tiny particles in a fluid due to collisions with atoms and molecules of the fluid • Law of Definite Proportions—chemical reactions always have integer values for the various substances. • Example: burning iron (Fe) in oxygen (O) produces iron oxide (Fe2O3) • We never have fractional values, such as Fe1/2O3/4 • Diffusion—atoms and molecules escaping from the substance and floating through the fluid to spread out. Chapter 2 Summary Particle model of matter also called kinetic model of matter Protons Atoms— Neutrons Electrons Molecules—combinations of atoms with covalent bonds Nucleus Chapter 2 Summary • Mass • amount of matter in an object • SI Unit: kilogram (kg) • fixed • Weight • measure of gravity acting on that object • SI Unit: Newtons (N) • varies with gravitation system Chapter 2 Summary Classification of Matter Pure Substances elements atoms ex: U, Fe, H Mixtures compounds molecules covalent bonds ex: H20, C12H22O11 heterogeneous mixtures crystal lattice ionic bonds ex: NaCl molecules ex: O2, Cl2, diamonds (carbon atoms) ex: granite, rocky road ice cream, Italian dressing homogeneous mixtures (solutions) ex: tea, smoothie, steel, salt water, air Chapter 2 Summary • Pure Substances • Elements–one type of atom • Compounds–molecular and ionic • chemically combined • Mixtures • Heterogeneous and Homogeneous • physically combined–can be separated • variable proportions–weak vs. strong tea. Chapter 2 Summary States of Matter • Kinetic Model because all particles are in motion • Kinetic ➔ motion • States of matter are dependent on: • Kinetic energy of particles (K.E.) • Attractive forces of the particles (A.F.) Chapter 2 Summary States of Matter • • • When K.E. < A.F. ➔ solid When K.E. ≈ A.F. ➔ liquid When K.E. > A.F. ➔ gas • Temperature drives the K.E. • Different substances have different states at a particular temperature because the attractive forces within the elements or compounds differ due to the unique chemical make-up of each compound. Chapter 2 Summary Solids Volume: Fixed Shape: Fixed Compressibility: Low Particle spacing: Close Density: high Particle Motion: vibrates in place Fluid?: no Chapter 2 Summary Liquids Volume: Fixed Shape: Changeable Compressibility: Low Particle spacing: Close Density: Between that of solid and gas Particle Motion: Slides past each other Fluid?: Yes Chapter 2 Summary Gas Volume: Changeable Shape: Changeable Compressibility: High Particle spacing: Widely spaced Density: low Particle Motion: High speed Fluid?: Yes Chapter 2 Summary Plasma • Gas-like state • High energy, high temperature ions and free electrons • Most common state of matter in universe-STARS Chapter 2 Summary • Changes in Matter • Law of Conservation of Matter • Matter cannot be created nor destroyed, just change form. • Chemical–New substance • Temperature changes • Gas produced • Color Changes • Physical Changes–No New Substance Chapter 2 Summary • Chemical Properties • how a substance changes in the presence of another substance or under certain conditions. • Reactivity • Flammability Chapter 2 Summary • Physical Properties • anything about a substance that can be observed or measured without altering the substance’s chemical composition. • • • • • Ductility Malleability Conductivity Luster State • • • • Triple Point Texture Color Density Changes of State Evaporation and Boiling Phase Diagram Practice Problems What is the density of a block of wood that has a mass of 560 g and a volume of 710 mL? Practice Problems What is the density of a block of wood that has a mass of 560 g and a volume of 710 mL? Known: m = 560 g V = 710 mL Unknown: d = ? m 560 g g d= = = .79 V 710 mL mL Practice Problems What is the volume of a lump of silver with a mass of 48 grams. The density of g silver is 10.49 mL Practice Problems What is the volume of a lump of silver with a mass of 48 grams. The density of g silver is 10.49 mL g mL Known: m = 48 g d = 10.49 Unknown: V = ? m m 48 g d= V= = g = 4.6 mL V d 10.49 mL Practice Problems What is the mass (in kg) of a brick of dry ice that is 1.45 liters? The density of dry g ice (solid CO2) is 1.561 . mL Practice Problems What is the mass (in kg) of a brick of dry ice that is 1.45 liters? The density of dry g ice (solid CO2) is 1.561 . mL g mL Known: V = 1.45 L d = 1.561 Unknown: m = ? m 1000 mL g d= m = V∙d = 1.45 L ( )(1.561 ) = 2,260 g V 1L mL 1kg m = 2,260 g ( ) = 2.26 kg 1000 g