CHAPTER 1 NOTES INTRODUCTION TO MATTER Lesson 1 – Describing Matter • Matter is anything that takes up space and has mass. •EVERYTHING IS MADE OF MATTER!!!! • Different properties or characteristics can be used to identify different types of matter. • Examples include: Hard or Soft • Hot or Cold • Solid, Liquid, or Gas • • Chemistry = the study of matter and how matter changes • Substance = a single kind of matter that is pure; meaning it always has a specific makeup or composition. • EX: Seawater Salt = Salt Mine •Physical vs. Chemical Properties: • Physical property is a characteristic of a substance that can be OBSERVED without changing it into another substance. • • Melting, freezing, dissolving, color, shape, size, mass, texture, hardness, state, luster, electrical , thermal conductivity Chemical property is a characteristic of a substance that describes its ability to change into different substances. • Ability to burn, rust, tarnish, sour, ferment – HOW IT REACTS How do you know if it is chemical or physical? •If it CHanges, it’s CHemical Lesson 2 – Classifying Matter • Scientists know that all matter in the universe is made of more than 100 different substances, called elements. • Element – a substance that cannot be broken down into any other substances by chemical or physical means. *Simplest substance* • Atom – the basic particle from which all elements are made from. • Molecule – a group of two or more atoms held together by chemical bonds. • Compounds – a substance made of tow or more elements that are chemically combined in a set ratio. Atoms vs Molecules Mixtures: made of two or more substances that are together in the same place, but their atoms are not chemically bonded. • Homogenous mixture – the substances involved are so evenly mixed that you can’t see the different parts. • • Examples: Honey, Soy sauce, air Heterogenous mixture – you can ussally see the different parts and easily separate out. • Examples: Salad, guacamole Separating Mixtures Substances (items or things) in a mixture keep their properties - Not chemically combined, just in same area (bowl, cup, etc.) Distillation (heating/cooling a liquid), evaporation, filtration, magnetic attraction Lesson 3 – Measuring Matter Weight vs. Mass Weight - Measure of the force of GRAVITY Planet Mass - - Amount of matter (stuff) in an object Does NOT change with location SI Units - Kilograms 1kg = 2.2 lbs Kilo = 1,000 Volume - Amount of space occupied by an object m3, L, mL Density - Measures of the mass of a material in a given volume - How compact is the substance? g/cm3 or g/mL - - Room Temp Water = 1g/cm3 Density = Mass/Volume Density SECTION 4 CHANGES IN MATTER Ch. 1 Introduction to Matter What Happens to a Substance in a Physical Change? Physical Change – Changes the form or the appearance of matter but not its identity Changes of State: - Solid, Liquid, Gas Changes in Shape or Form - Dissolving sugar in water Physical Changes Examples: - Crushing a can Breaking glass Mixing sand and water Shredding paper Chopping wood What Happens to a Substance in a Chemical Change? Chemical Change: Change in matter that produces one or more NEW substances - ***Cannot be reversed**** - Photosynthesis: Sunlight + Water + CO2 → Oxygen + Sugar Combustion (burning) produces CO2 & Water (gas) Souring MIlk, Cooking, rust, digesting food Law of Conservation of Mass Mass/matter/energy CANNOT be created nor destroyed - Can be used or transformed into a different form/shape/substance The mass on one side of an equation has to be the same on both sides of an equation - CH4 + 2O2 → CO2 + 2H2O Conservation of Mass How Are Changes in Energy and Matter Related? Every chem & phys change in matter includes a change in energy - It takes energy to make these changes Energy is either gained or lost - System (object that is being studied) Surroundings (environment around the object) Temperature & Energy Temp: MEASURES hot & cold - Due to the energy of motion of the particles (faster motion = higher temps) Thermal Energy: total energy of motion of all the particles in an object (Why does something FEEL hot/cold?) Thermal Energy & Changes in Matter Thermal Energy Endothermic: (ENTER) - energy is absorbed by the system Makes the surroundings feel cold Exothermic: (EXIT) - energy is released by the system Makes the surroundings feel hot Transforming Chemical Energy Chemical bonds that form between atoms have chemical energy - Foods, fuels, cells of body - Energy from these bonds translates to - Heat energy (lost during activity) Energy of motion (walking, running, biking, etc.) Life processes (breathing, excreting waste, cell division, etc.)
