![]() However, the composition of both is H 2O, so freezing/melting point is a physical property. For example, when you freeze water to observe the freezing/melting point, you notice that ice and water appear very different from one another. But even this can be tricky because some substances change their appearance leading you to think that the composition changed when it didn’t. If the answer is “no”, then you observed a chemical property. The best question to ask yourself when trying to decide if something is a chemical or physical property is this one: “After I observe the property, do I still have the same substance with the same composition?” If the answer is “yes”, then you observed a physical property. Unfortunately, sometimes it can be tricky to decide between the two types of properties. (Au + H 2O -> no reaction) This is nice to know since so much of our jewelry is made from gold! For example, gold metal doesn’t react with water at all. Sometimes it is very important to know that a material doesn’t possess a chemical property. There is a “flip side” to chemical properties that should be considered. (2Na + 2H 2O -> H 2 + 2NaOH) This reaction produces a change in composition as neither of the substances produced has the same make-up as the original water or sodium. For example, sodium metal reacts vigorously with water to produce hydrogen and sodium hydroxide. Another way of saying this is that chemical properties determine the changes that substances undergo when they participate in chemical reactions. For example, we can say that water is a colorless, odorless, tasteless gas (qualitative) that freezes at 0 oC and boils at 100 oC (quantitative).Ĭhemical properties are those characteristics that can only be observed when the substance is undergoing a change in composition. Both qualitative adjectives and quantitative numbers can be used when we list physical properties. There are dozens of different physical properties, but odor, color, texture, and boiling point are some familiar ones. Physical properties are those characteristics that we can observe and measure without changing the composition of the substance. So let’s look at these properties in more detail. If asked to distinguish between the two types, you might have some difficulty deciding if a property is physical or chemical. You might already be familiar with some physical and chemical characteristics, but others you’ve maybe never heard of. We use these properties to help us identify materials as well as describe them. In order to understand and use the many materials around us, we need an understanding of their physical and chemical characteristics or properties. Single Replacement Reactions - Practice w/ Answers.Single Replacement Reactions - animation.Reactions - Take a "Quiz" and get a % score.Reactions Quiz - ID the 4 Types of Reactions.Video - 5 Types of Reactions (You Tube - watch at home).Video - Classifying Reaction Types (You Tube - watch at home).Answers to Balancing Equations Practice.Balancing Equations - Practice #3 ("worksheet").Balancing Equations - Practice #2 (w/ info/help).Balancing Equations - Practice #1 (game).Determning Empirical Formula from Elemental Analysis.Determining Empirical Formula from Molecular Formula.Percentage Composition - "everyday examples" Video.Percentage Composition - "how to" Video.How to Determine Charges Video - Tyler Dewitt.Metallic Bonding 3 - Info (esp Properties) with Animation. ![]() Metallic Bonding 2 - Info with Animation.Determing Oxidation Numbers (Charge) Video.Chapter 5c - Ionization Energy & Electron Affinity.Clickable Periodic Table showing Trends.Notes - Atomic Structure & the Periodic Table.Video - Periodic Changes in Atomic Size.Alternative Forms of the Periodic Table. ![]() Discovering the Elements - Table with Slider. ![]()
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