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Elements Objectives Describe what elements are. Give examples of common elements. Make a model that relates the particle model to a familiar property of.

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Presentation on theme: "Elements Objectives Describe what elements are. Give examples of common elements. Make a model that relates the particle model to a familiar property of."— Presentation transcript:

1 Elements Objectives Describe what elements are. Give examples of common elements. Make a model that relates the particle model to a familiar property of matter.

2 Elements High in the Rocky Mountains or on the streets of New York City, the oxygen in the air you breathe is the same. The air is different, but the oxygen atoms in both places have the same properties. All oxygen atoms have eight protons and eight electrons.

3 Elements element.Oxygen is an element. As you have learned, elements are the basic kinds of matter in the universe. An element is a substance made of just one kind of atom. It cannot be broken down or changed by chemical means.

4 Elements and Matter Even though all matter is made up of elements, only a few elements exist in nature in their pure form. You may remember that the oxygen and nitrogen in air are elements. Diamond is a natural form of the element carbon. Occasionally pure deposits of silver, gold, or copper are found.

5 Elements and Matter You would probably not recognize most elements in their pure form because most elements in nature are combined with other elements.

6 Elements and Matter Of the more than 100 known chemical elements, only about 30 play an important role in your daily life. About 18 elements do not occur in nature. They are created in laboratories and known as synthetic elements.

7 Properties of Elements The properties used to describe the elements in their pure forms include luster, texture, color, density and the ability to conduct electricity. Elements differ in how they react with other elements. Most elements are solids but some are gases and others are liquids.

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9 Objectives Describe the properties of a compound. Give examples of common compounds. Define operationally the composition of a compound by writing its chemical formula. Compounds

10 Nearly all the products you use are made of more than one element. The clothes you wear, the food you eat for breakfast, and the toothpaste you use to brush your teeth are all combinations of elements. Almost everything you can think of is made up of some combination of elements. Compounds

11 There are millions of compounds in, on, and around the earth. Many compounds are found in living things. Compounds also make up most of the nonliving world. Water is a compound. ompounds Defining Compounds

12 How are compounds formed? Many are created by geologic processes deep in the earth. Organisms must manufacture compounds to stay alive. Plants are always making the compound glucose. Many products you buy are made of compounds that aren't found in the natural world. For example, if you look at the list of ingredients on food packages you will probably see some compounds you don't recognize. People create these compounds in factories and chemical plants. ompounds Defining Compounds

13 The properties of a compound are different from those of the elements that make it up. Hydrogen and oxygen are both gases. but they combine to form water. The elements that make it up always combine in a specific proportion. Carbon dioxide is two parts oxygen and one part carbon (CO 2 ). ompounds Properties of Compounds

14 Properties of Compounds Study the text and photographs on pg. 169 Answer on a separate piece of paper: - What is the difference between the compounds carbon dioxide and carbon monoxide? -How does the compound sodium chloride differ from the elements sodium and chloride? -What compound is common in rocks, and what elements does the compound contain? -What is the natural form of calcium carbonate, and what three elements make it up?

15 Properties of Compounds Study the text and photographs on pg. 169 Answer on a separate piece of paper: - CO2 has 2 atoms of oxygen and 1 atom of carbon and CO has one C & one O. -NaCl2 is table salt, an edible crystal. Sodium is a silvery metal and chlorine is a poisonous gas. -Silicon Dioxide; silicon and oxygen. -Limestone; Calcium, carbon and oxygen.

16 Compounds differ in the kinds of atoms that make them up. Compounds also differ in the way the atoms are joined. Compounds can be classified into two groups based on how their atoms are bonded, or joined to each other. 1. Molecular Compounds (covalent bond)1. Molecular Compounds (covalent bond) 2. Ionic Compounds2. Ionic Compounds ompounds Types of Compounds

17 Types of Bonds IONIC BONDS Transfer of electrons. Elements “take” electrons from other elements COVALENT BONDS Sharing of electrons.

18 A chemical formula is a combination of symbols and numbers that represent the composition of a compound. The symbols show the kinds of atoms in the compound. The numbers, called subscripts, show the number of each kind of atom. When more than one atom of an element is present in a compound, a subscript is written to the right and below the element's symbol. If there is only one atom of the element, no subscript is used. ompounds Formulas of Compounds

19 How do you write a formula for a compound? You need to know what it made of. A molecule of carbon dioxide, for example, has one atom of carbon and two atoms of oxygen. The formula is CO 2. ompounds Formulas of Compounds

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21 November #__ Word Sort: Write 3 sentences with at least 3 words in each sentence. Once a word is used you CAN’T use it again! Element, proton, compound, covalent bond, periodic table,13, atomic number, neutron, atomic mass, carbon, electron, ionic compound, Rutherford, nucleus, atom, symbol, aluminum, 6, Thomson, subscript, sharing, taking/giving, positive, negative, 14, mass number

22 Objectives Compare and contrast mixtures and compounds. Distinguish between homogeneous and heterogeneous mixtures. Define operationally a method for separating a mixture. Mixtures

23 11/24/14 Do Now # __ What is an element? What is a compound? Give 2 examples of compounds?

24 How is a mixture different from a compound? The different parts of a compound -either atoms or ions- are combined chemically. The different parts of a mixture, in contrast, are simply mixed together. Comparing Mixtures and Compounds

25 Also, mixtures and compounds differ in other ways: 1.The makeup, or composition, of a mixture can vary. The composition of a compound, on the other hand, is constant. 2.The components of a mixture keep their original properties. You can still taste the sodium chloride dissolved in sea water. A compound, however, has properties different from the elements that make it up. Comparing Mixtures and Compounds

26 3.Because the components of a mixture are not combined chemically, they can usually be separated by physical means. Distillation and filtering are examples of physical means used to separate mixtures. 4.In contrast, the elements in a compound must usually be separated by chemical means, such as the addition of heat energy. http://chrome.brainpop.com/science/matterandche mistry/compoundsandmixtures/preview.weml Comparing Mixtures and Compounds

27 There are several types of mixtures:.Homogenous 1.Homogenous2.Heterogeneous3.Alloys Types of Mixtures

28 All parts of a homogeneous mixture contain the same amount of each component. Most mixtures formed by dissolving a compound in a liquid are homogeneous mixtures. Perfume is a homogeneous mixture of dozens of fragrance compounds dissolved in alcohol. Homogenous Mixtures

29 Not every part of a heterogeneous mixture has the same composition. One part of the mixture has more of one component than another. Cooking spices are often a heterogeneous mixture of many herbs mixed together. Heterogeneous Mixtures

30 alloyDifferent metals can be combined to form a special kind of mixture, called an alloy. An alloy is made by heating two or more metals until they melt together. All coins are made of alloys. Alloys

31 Link the Concepts ? has Electron Cloud nucleus Contains ? ?? charge ???

32 Link the Concepts Atom has Electron Cloud nucleus Contains ? ?? charge ???

33 Link the Concepts Atom has Electron Cloud nucleus Contains electrons ?? charge ???

34 Link the Concepts Atom has Electron Cloud nucleus Contains electrons ?? charge negative??

35 Link the Concepts Atom has Electron Cloud nucleus Contains electrons protons? charge negative??

36 Link the Concepts Atom has Electron Cloud nucleus Contains electrons protons? charge negativepositive?

37 Link the Concepts Atom has Electron Cloud nucleus Contains electrons protonsneutrons charge negativepositive?

38 Link the Concepts Atom has Electron Cloud nucleus Contains electrons protonsneutrons charge negativepositiveneutral

39 12/1/14#__ 1. What are the 3 particles that make up an atom? What are their charges? Where are they found? 2. How are elements arranged on the periodic table? 3. What is the difference between a compound and a mixture? 4. What are the 2 main types of mixtures?

40 November 19 th # __ What is the difference between a compound and a mixture? What is 1 example of a compound? What is 1 example of a mixture? –THINK, PAIR, SHARE- DISCUSS YOUR ANSWERS.

41 Class Procedure- Mixture Madness 1. Separate the beans 2. Take out iron with magnet 3. Transfer salt and sand to empty beaker 4. Add 10 mL water to sand and salt mixture 5. Filter out the sand from the salt water 6. Boil off the water leaving the salt

42 Exit Ticket: #1 What is 1 property of sand? What is 1 property of salt? What is 1 property of iron?

43 Exit Ticket: #2 What is 1 property of iron? Is salt a compound or a mixture? WHY? What type of MIXTURE were we dealing with today? WHY?


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