Picture of Matter Chemistry is the science that explains the structure and properties of matter. – What is Matter? Examples: – Water – Popcorn – Bus
Matter The submicroscopic view of matter: – Those tiny balls represent atoms!
Models Models connect the macroscopic (macro=big)and microscopic (micro=small) views.
Classifying Matter Qualitative observation: Made without measurement – Examples: Color, size, shape. What qualitative things do you see?
Classifying Matter cont… Quantitative observations uses measurements – Examples: Mass or weight, time, temperature
Pure Substance v. Mixture Pure substance is matter with the same fixed composition and properties. – Examples: A bag of sugar, glass, pure water – Which of the following shows a pure substance?
Mixture (mixed matter) A mixture is a combination of two or more substances (two substances don’t interact) – Examples: sand and sugar, dirt, blood, milk.
How can you separate mixtures? Physical properties/change: characteristics or changes of matter that don’t change its identity. – Separate the Chex mix physically by size, shape, floatation?
Two kinds of Mixtures Heterogeneous Mixtures – different compositions – Hetero = different Homogeneous Mixtures – same compositions – Homo = same
Homogeneous or Heterogeneous?
Homogeneous=solutions Solutions contain two parts (solute and a solvent) – Example = Gatorade – Solute = substance being dissolved Example = Sugar/electrolytes – Solvent = Dissolves solvent Example = Water
Other Mixtures Alloys = solid solutions that contain different metals. – Examples: Spinners, brass, stainless steel
Why mix metals?
Pure Substances Elements = cannot be broken down into simpler substance – Building block for other forms of matter All substances are made from elements See Periodic Table (all known elements)
Compound (another pure substance) Compounds = Can be broken down into elements Elements are bonded together in fixed proportions Examples: H 2 O, CH 4, NaCl
Vocabulary Quiz. Matching DefinitionWord Bank (some extra words) 1. A combination of two or more substances in which each part is not changed. 2. Takes up space and has mass. 3. Descriptive observations like color, size and texture 4. The study of matter! Everyone’s favorite class. 5. Characteristics (or properties) of matter that when changed are reversible. Example: metal bending. Chemistry Qualitative Quantitative Matter Physical Property Mixture Chemical Property Math
C1 Section 2 Vocabulary Volatile Density Chemical property Chemical change Chemical reaction Law of conservation of mass Energy Exothermic endothermic
C1 Section 2 Properties and Changes of Matter States of Matter – Solid – Liquid – Gas – Plasma
Properties of Matter Volatile = a liquid that can easily change to gas at room temperature – Example = Gasoline
Properties of Matter… Density = Amount of matter contained in a unit of volume – Physical property – Equation: Density = mass/volume
Chemical Properties Chemical Change = changing a substance into another substance – Not easily reversible – Involves chemical reactions – Changes chemical property Example: Iron rusts
Chemical Change and Energy Energy = capacity to do work Exothermic = Gives off energy – Feels hot Endothermic = Absorbs energy – Feels cold
C1-2 Vocabulary Quiz DefinitionWord Bank 1.The amount of matter per unit of volume (g/mL). 2.Matter is neither created nor destroyed. 3.The change of one or more substances into other substances. 4.A chemical reaction that absorbs energy making the container feel cold. 5.A chemical reaction that releases energy making the container feel hot. -Volatile -Endothermic reaction -Chemical reaction -Exothermic reaction -Law of conservation of mass -Energy -Density -Chemical Reaction