Unit 1- Elements and Compounds Lesson 1- What Are Atoms and Elements? y0m7jnyv6U

California State Standards: 1) Elements and their combinations account for all the matter in the world. As a basis for understanding this concept: –1.b) Students know all matter is made of atoms, which may combine to form molecules. – 1.d) Students know that each element is made of one kind of atom and that the elements are organized in the periodic table by their chemical properties. – 1.f) Students know differences in chemical and physical properties of substances are used to separate mixtures and identify compounds

Disneyland, California Some theme parks in California have fireworks displays. Fireworks are very colorful because they contain different elements. Each element burns with a different color. The element strontium burns with a red color. Calcium burns orange, and sodium produces a yellow color.

Language of the Discipline Atom- the smallest unit of an element that has the properties of that element.

Language of the Discipline Element- a substance made of only one kind of atom.

Language of the Discipline Periodic Table- shows the elements arranged by their atomic numbers.

Language of the Discipline

Compound- a substance made of two or more different elements.

Language of the Discipline Molecule- a group of two or more atoms that are joined.

Language of the Discipline Physical property- a trait- such as a color, shape, or hardness, that describes a substance by itself.

Language of the Discipline Mixture- a combination of two or more different substances.

Atoms and Elements Big Idea- –All matter is made up of atoms.

Atoms and Elements Centuries ago, Greek thinkers wondered about the smallest unit of matter, which they called an atom. –An atom is the smallest unit of an element. –It consists of smaller particles known as protons (+), neutrons, and electrons (-)

Atoms and Elements In an atom, all the protons, neutrons, and electrons are alike.

Atoms and Elements When these particles combine, an element is formed. An element is the simplest form of matter because it contains only one type of atom. –Examples: Carbon, Oxygen, Iron, Hydrogen

Atoms and Elements The relationship between atoms and elements can be compared to a building.

Atoms and Elements The relationship between atoms and elements can be compared to a building. - Atoms = bricks -Elements = building

Atoms and Elements Each type of atom has the properties of a certain element. –Carbon atoms have the properties of carbon. –Gold atoms have the properties of gold.

Atoms and Elements Elements are given names based on the combination of the protons, neutrons, and electrons. –The number of protons an atom has determines the element. –This is known as the element’s atomic number.

Atoms and Elements An element name can be written in a short form— with one to three letters that stand for that element. The symbol is the first few letters of the name. For others, such as iron (Fe), the symbol comes from the original Latin or Greek name for the element

Atoms and Elements The early Greeks thought there were four elements- earth, air, water, and fire. Today, we know there are more than 100 elements. –They combine to form millions of substances. –Only a slight few exist in their pure form in nature.

Show What You Know Describe what an atom is and what it consists of.

Show What You Know Describe what an atom is and what it consists of. –An atom is the smallest unit of an element that has the properties of that element that contains protons, neutrons, and electrons.

Show What You Know What is an element? Provide a few examples of different elements.

Show What You Know What is an element? Provide a few examples of different elements. –An element is a substance made of only one kind of atom. A few examples are Carbon, Hydrogen, and Iron.

Show What You Know What is the relationship between atoms and elements?

Show What You Know What is the relationship between atoms and elements? –Atoms are the building blocks to the different types of elements.

Show What You Know How do you determine the element? –A) The number of electrons –B) The number of protons –C) The number of electrons –D) None of the above.

Show What You Know How do you determine the element? –A) The number of electrons –B) The number of protons –C) The number of electrons –D) None of the above.

Summary Time! Write a summary about what you learned today. Be sure to: –Use complete sentences –Use proper punctuation –Answer in paragraph form

The Periodic Table

Big Idea: –The periodic table is used to organize and categorize elements based on their chemical properties.

The Periodic Table As we learned earlier, –Elements are the building blocks of matter.

The Periodic Table As we learned earlier, –Elements are the building blocks of matter. –They combine to form millions of substances.

The Periodic Table As we learned earlier, –Elements are the building blocks of matter. –They combine to form millions of substances. –Everything in the world is made from combinations of the same element.

The Periodic Table Atoms of each element have a certain number of protons. For example: –Each hydrogen atom has only one proton. –Each iron atoms has 26 protons. The number of protons is the element’s atomic number.

The Periodic Table The elements are arranged in order of the atomic number on a chart called the periodic table. –“periodic” means repeating in a pattern. – Atomic numbers increase as you move across a row and down a column. –You would read the periodic table like a book, from left to right.

The Periodic Table Each element has its own box that includes the atomic number, the name, and the symbol. ELEMENT’S NAME ATOMIC NUMBER SYMBOL

The Periodic Table Which element has 12 protons? What is the atomic number for copper (Cu)?

The Periodic Table The periodic table tells us a lot about each element.

The Periodic Table The periodic table tells us a lot about each element. The left side of the table are metals. The right side of the table are non-metals. Many of these are gases.

The Periodic Table The elements in each column of the table have similar chemical properties. –Example: the elements in the column 1 are soft metals that can be cut by a knife. Because of these similarities, scientists can predict what the elements will be like.

Show What You Know In your own words, describe the periodic table.

Show What You Know In your own words, describe the periodic table. –Answers will vary but the main idea is that the elements are arranged on the table based on their chemical properties.

Show What You Know How are the elements arranged on the periodic table?

Show What You Know How are the elements arranged on the periodic table? –The elements are arranged on the periodic table based on their atomic number.

Show What You Know What are some ways you can locate an element on the periodic table?

Show What You Know What are some ways you can locate an element on the periodic table? –You could locate an element on the periodic table based on it’s atomic number, chemical properties, or based on whether the element is a metal, non-metal, or gas.

Summary Time Write a summary about what you learned today. Be sure to: –Use complete sentences –Use proper punctuation –Answer in paragraph form

Molecules and Compounds

Big Idea –Pure substances are made of molecules and compounds.

Molecules and Compounds As we previously learned, elements are rarely found in their pure form in nature.

Molecules and Compounds As we previously learned, elements are rarely found in their pure form in nature. –Most are found in compounds- a combination of two or more elements that has been combined chemically.

Molecules and Compounds As we previously learned, elements are rarely found in their pure form in nature. –Most are found in compounds- a combination of two or more elements that has been combined chemically. Two elements combine to make one substance.

Molecules and Compounds Think of compounds like compound words. A compound word is made up of two words that make up a new word. Like a compound word, compounds are two elements that combine to make a new substance.

Molecules and Compounds Different compounds have different formulas. –Example: Water = H 2 0 Table Salt = NaCl

Molecules and Compounds The same atoms can combine to form different compounds. –Example: Carbon and Hydrogen –CH 4 = MethaneC 3 H 8 = Propane

Molecules and Compounds Gases can also combine to form compounds. –Hydrogen and oxygen are both gases. –When they combine, nothing happens unless heat is added.

Molecules and Compounds Pure substances include compounds and molecules. –A molecule is a group of two or more atoms that are joined. –The numbers after the element's symbol tell how many atoms are in a single molecule. –Example: CH 4

Molecules and Compounds An example of a molecule is a water molecule.

Show What You Know In your own words, explain what a compound is.

Show What You Know In your own words, explain what a compound is. –Answers may vary but the main idea is that compounds are a combination of two or more elements.

Show What You Know In your own words, explain what a molecule is.

Show What You Know In your own words, explain what a molecule is. –Answers may vary, but the main idea is that molecules are the combination of two or more atoms.

Show What You Know What causes two gases to combine?

Show What You Know What causes two gases to combine? –Heat causes two gases to combine.

Summary Time Write a summary about what you learned today. Be sure to: –Use complete sentences –Use proper punctuation –Answer in paragraph form

Physical Properties Big Idea Physical properties are used to describe a particular object or substance.

Physical Properties Look around the room and chose one object. Observe this object for about a minute or so. How would you describe the physical features of that object?

Physical Properties When we observe objects, we use our five senses. –Example: A clock Round shape Hard glass cover Black numbers Moving small and big hands Constantly moving second hand

Physical Properties When describing an object, we describe the physical properties of that object. –Physical properties are traits that describe a substance by itself.

Physical Properties When describing an object, we describe the physical properties of that object. –Physical properties are traits that describes a substance by itself. –Some physical properties cannot be observed directly. Example: temperature and mass

Physical Properties The physical properties of a substance can change. –This is known as a physical change.

Physical Properties The physical properties of a substance can change. –This is known as a physical change. –Example: water

Physical Properties The physical properties of a substance can change. –This is known as a physical change. –Example: water Solid Liquid Gas

Physical Properties  Even though the form changes, the substance does not. –The substance in all three pictures are water, just in different forms.

Physical Properties Another physical property is solubility, the ability to dissolve.

Physical Properties Another physical property is solubility, the ability to dissolve. –Sugar can dissolve in water; sand cannot. –The terms “dissolve” and “mix” are clues a physical change has occurred.

Physical Properties Another physical property is solubility, which is the ability to dissolve. –Sugar can dissolve in water; sand cannot. –The terms “dissolve” and “mix” are clues a physical change has occurred. –Mixtures are combinations of two or more substances that can be separated.

Show What You Know In your own words, describe a physical property.

Show What You Know In your own words, describe physical properties. –Answers may vary but the main idea is that a physical properties are traits that describe a substance or object.

Show What You Know Explain some physical properties and give examples.

Show What You Know Explain some physical properties and give examples. –Sight: The clock looks round –Touch: The desks are hard –Taste: The coffee is sweet

Show What You Know What are physical properties that cannot be observed?

Show What You Know What are physical properties that cannot be observed? –Temperature and mass cannot be observed.

Show What You Know Does the physical properties of a substance always stay the same? Give an example to defend your answer.

Show What You Know Does the physical properties of a substance always stay the same? Give an example to defend your answer. –No, physical properties of a substance do not always stay the same. This is known as a physical change. An example would be water.

Show What You Know Describe the term solubility. How does this relate to physical properties?

Show You What Know Describe the term solubility. How does this relate to physical properties? –Solubility is the ability to dissolve. This property describes different substances.

Summary Time Write a summary about what you learned today. Be sure to: –Use complete sentences –Use proper punctuation –Answer in paragraph form