Matter

What is Matter? Matter is anything that takes up space and has mass Matter is anything that takes up space and has mass Some matter you can see (your lab table) and some you cannot (the air around you) Some matter you can see (your lab table) and some you cannot (the air around you) Matter varies in characteristics because of the atoms that make it up Matter varies in characteristics because of the atoms that make it up Atoms are “building blocks” of matter Atoms are “building blocks” of matter Element- substance that cannot be broken down into simpler substances by chemical or physical means (iron, copper, hydrogen) Element- substance that cannot be broken down into simpler substances by chemical or physical means (iron, copper, hydrogen)

Periodic Table- Organizes the Elements

Periodic Table 112 known elements 112 known elements 92 naturally occur and others are produced in the lab 92 naturally occur and others are produced in the lab The periodic table is organized by periods (rows) and groups (columns) The periodic table is organized by periods (rows) and groups (columns)

Organizing the Squares GROUPGROUP P E R I O D S Horizontal Rows VERTICALVERTICAL COLUMNSCOLUMNS

Organizing the Squares The Periods  The table has 7 periods (rows)  1 st period has 2 elements  2 nd period has 8 elements  3 rd period has 8 elements  4h period has 18 elements  etc

The Groups  Groups are numbers from 1 to 18 from left to right  Some groups are given family names  Notice the different colors on the table below  Group 1=Alkali metals  Group 2= Alkali Earth Metals  etc Organizing the Squares

Metals, non-metals, and semimetals  Metals – shiny, good conductors of heat and electricity, solid (Hg liquid), etc  Non-metals – do not have properties above  Semimetals – or metalloids – have some properties of metals

Elements Each element is represented by a symbol Each element is represented by a symbol Each element also has an atomic number which represents the number and protons and a mass number which represents the mass (and number) of protons + neutrons Each element also has an atomic number which represents the number and protons and a mass number which represents the mass (and number) of protons + neutrons The number of electrons in an atom will equal the number of protons, (unless the atom is an ion) The number of electrons in an atom will equal the number of protons, (unless the atom is an ion)

The most abundant elements in Earth’s crust Element Approximate % by weight Oxygen46.6 Silicon27.7 Aluminum8.1 Iron5.0 Calcium3.6 Sodium2.8 Potassium2.6 Magnesium2.1 All others1.5

Atoms and Matter Atoms- Nucleus + Electrons Atoms- Nucleus + Electrons Nucleus- contains protons and neutrons Nucleus- contains protons and neutrons

Protons and Neutrons- Nucleus Protons have a (+) charge Protons have a (+) charge The number of protons in an atom of an element is equal to the atomic number of the element The number of protons in an atom of an element is equal to the atomic number of the element Neutrons are neutral (they have no charge) Neutrons are neutral (they have no charge) Mass of individual protons is approximately 1 and mass of individual neutrons is approximately 1 Mass of individual protons is approximately 1 and mass of individual neutrons is approximately 1 Mass number = mass of protons + neutrons (and) number of protons + neutrons Mass number = mass of protons + neutrons (and) number of protons + neutrons

Electrons- Surround the nucleus The smallest of the fundamental particles of an atom The smallest of the fundamental particles of an atom The part of the atom involved in chemical bonding The part of the atom involved in chemical bonding Mass- 1/1836 the mass of a proton or electron Mass- 1/1836 the mass of a proton or electron Electrons move so rapidly around the nucleus that they create a sphere Electrons move so rapidly around the nucleus that they create a sphere shaped zone shaped zone

Electrons The number of electrons in an atom is always the same as the number of protons- unless the atom is an ion The number of electrons in an atom is always the same as the number of protons- unless the atom is an ion Ions- have extra electrons (giving the ions a negative charge) or have less electrons (giving the ions a positive charge) Ions- have extra electrons (giving the ions a negative charge) or have less electrons (giving the ions a positive charge) Examples- Ca +2, Na +, Cl - Examples- Ca +2, Na +, Cl - Which of these has extra electrons? Which have electrons taken away? Which of these has extra electrons? Which have electrons taken away?

Calculating number of Protons, Neutrons, and Electrons Carbon (C) has an atomic number of 6 and an atomic mass of Carbon (C) has an atomic number of 6 and an atomic mass of How many protons? How many neutrons? How many protons? How many neutrons? How many electrons? How many electrons? Gold (AU) has an atomic number of 79 and an atomic mass of Gold (AU) has an atomic number of 79 and an atomic mass of How many protons? How many neutrons? How many protons? How many neutrons? How many electrons? How many electrons?

Isotopes Isotopes are atoms that have the same number of protons, but have different numbers neutrons. The mass number of these atoms would be different Isotopes are atoms that have the same number of protons, but have different numbers neutrons. The mass number of these atoms would be different Carbon has 15 different isotopes Carbon has 15 different isotopes Carbon 12 makes up 99% of the carbon on Earth and has 6 protons and 6 neutrons Carbon 12 makes up 99% of the carbon on Earth and has 6 protons and 6 neutrons Carbon 13 has 6 protons and 7 neutrons Carbon 13 has 6 protons and 7 neutrons Carbon 14 has ? Protons and ? neutrons Carbon 14 has ? Protons and ? neutrons

Chemical Bonding and States of Matter 11. Energy – the ability to do work 12. Potential energy – stored energy due to position or location 13. Orbital – the 3D space in which an electron has a good probability of being found 14. Valence electrons – the outer most shell of electrons 15. Covalent bonds – atoms that combine by sharing valance electrons

16. Ionic bond – a type of bonding in which one atom strips away an electron from another atom 17. Ion – a charged atom 18. Chemical reaction – the making and breaking of chemical bonds 19. Reactants – the starting materials in a chemical reaction 20. Products – the result of a chemical reaction 20

Atomic Theory of Matter Dalton's Atomic Theory (John Dalton, English chemist, ) Dalton's Atomic Theory (John Dalton, English chemist, ) 1) All matter is made of atoms. Atoms are indivisible and indestructible. 1) All matter is made of atoms. Atoms are indivisible and indestructible. 2) All atoms of a given element are identical in mass and properties 2) All atoms of a given element are identical in mass and properties 3) Compounds are formed by a combination of two or more different kinds of atoms. 3) Compounds are formed by a combination of two or more different kinds of atoms. 4) A chemical reaction is a rearrangement of atoms. 4) A chemical reaction is a rearrangement of atoms.

Modern Atomic Theory Dalton’s theory remains valid, but modern theory is more descriptive Dalton’s theory remains valid, but modern theory is more descriptive 1) atoms can be destroyed by nuclear reactions, but not chemical reactions 2) there are different forms of atoms of elements called isotopes which have the same properties

23 How compounds form  Individual atoms combine in a process called chemical bonding.  The type of bond is determined by how many electrons are found in the outermost energy level (orbital).

24 Chemical Bonding Valence Electrons- the electrons on the outer orbital of an atom which may participate in chemical bonding. Valence Electrons- the electrons on the outer orbital of an atom which may participate in chemical bonding. All other electrons are known as inner-shell electrons All other electrons are known as inner-shell electrons

25 Chemical Bonding Label the valence electrons on your periodic table Label the valence electrons on your periodic table

26 Octet Rule Octet Rule- The tendency for atoms of elements to gain, lose, or share electrons so that their outer orbital (valence orbital) is full with eight electrons. Octet Rule- The tendency for atoms of elements to gain, lose, or share electrons so that their outer orbital (valence orbital) is full with eight electrons. There are a few exceptions: Hydrogen, Helium, Lithium, and Beryllium ions have outer shells that need only 2 electrons to be full. There are a few exceptions: Hydrogen, Helium, Lithium, and Beryllium ions have outer shells that need only 2 electrons to be full.

27 Chemical Bonding Atoms gain, share, or lose electrons to get 8 electrons in their outer shells to become STABLE. Atoms gain, share, or lose electrons to get 8 electrons in their outer shells to become STABLE. When they do this, they form bonds When they do this, they form bonds There are 3 main types of bonds There are 3 main types of bonds Ionic Bonds Ionic Bonds Covalent Bonds Covalent Bonds Metallic Bonds Metallic Bonds

28 Remember… Protons are Positively charged (p + ) Protons are Positively charged (p + ) Electrons are Negatively charged (e - ) Electrons are Negatively charged (e - ) An atom has equal number of positive and negative charges. An atom has equal number of positive and negative charges. Same number of protons and electrons. Same number of protons and electrons. Atoms are electrically neutral, but they can gain or lose electrons to become ions. Atoms are electrically neutral, but they can gain or lose electrons to become ions.

29 Ionic Bonds

30Ions Ion- an atom or group of atoms that has an electric charge because it has lost or gained electrons Ion- an atom or group of atoms that has an electric charge because it has lost or gained electrons Cation- an ion that has a positive charge. Cation- an ion that has a positive charge. More protons than electrons. More protons than electrons. Anion- an ion that has a negative charge. Anion- an ion that has a negative charge. More electrons than protons. More electrons than protons.

31 Ionic Compound Any chemical compound that is composed of oppositely charged ions. Any chemical compound that is composed of oppositely charged ions. Elements in groups 1 and 2 and in groups 16 and 17 will almost always form ionic compounds. Elements in groups 1 and 2 and in groups 16 and 17 will almost always form ionic compounds. The force of attraction between the ions’ positive and negative charges create an ionic bond. The force of attraction between the ions’ positive and negative charges create an ionic bond. Ionic bonding occurs between metals and nonmetals. Ionic bonding occurs between metals and nonmetals. Metals usually lose electrons and nonmetals gain electrons. Metals usually lose electrons and nonmetals gain electrons.

32 Ions It is easy to tell which ion an element will form based on their group number Group 1= +1 Group 1= +1 Group 2 = +2 Group 2 = +2 Group 13 = +3 Group 13 = +3 Group 14 = doesn’t usually form ions Group 14 = doesn’t usually form ions Group 15 = -3 Group 15 = -3 Group 16 = -2 Group 16 = -2 Group 17 = -1 Group 17 = -1 Group 18 = doesn’t usually form ions Group 18 = doesn’t usually form ions

33 Ionic Bond

34 Chemical Formulas for Ionic Bonds If the charges of the ions cancel out, then you can just write the element symbols together: If the charges of the ions cancel out, then you can just write the element symbols together: Na +1 + Cl -1 = NaCl Na +1 + Cl -1 = NaCl

35 Chemical Formulas for Ionic Bonds If they are not equal, then the superscript of one ion becomes the subscript of the other ion: If they are not equal, then the superscript of one ion becomes the subscript of the other ion: Ca +2 + Cl -1 Ca +2 + Cl -1 = CaCl 2 = CaCl 2 Notice that 1 is not written Notice that 1 is not written

36 Covalent Bonding Occurs between nonmetal and nonmetal

Covalent Bonds – A covalent bond is formed when atoms share electrons A covalent bond is formed when atoms share electrons Atom is unstable when the outside energy level is not filled Atom is unstable when the outside energy level is not filled Hydrogen atoms H2H2 Molecule: A group of atoms held together by covalent bonds (they have no overall charge) Example - Individual hydrogen atoms have 1 electron but want 2. In this state they are unstable. By sharing electrons they are stable.

38 Covalent Bond Neither atom in a covalent bond has enough attraction to completely take an electron from the other atom (to become an ion); so the electrons are shared. Neither atom in a covalent bond has enough attraction to completely take an electron from the other atom (to become an ion); so the electrons are shared. Because the atoms share electrons, covalent bonds are much stronger than ionic bonds. Because the atoms share electrons, covalent bonds are much stronger than ionic bonds. Atoms in covalent bonds can share 1, 2, or 3 pairs of electrons. Atoms in covalent bonds can share 1, 2, or 3 pairs of electrons. The more electrons are shared, the stronger the bond between the atoms. The more electrons are shared, the stronger the bond between the atoms.

39 Review Chemical Bonds Covalent VS Ionic Bonds

Metallic Bonds are… How metal atoms are held together in a solid. How metal atoms are held together in a solid. Metals hold on to their valence electrons very weakly. Metals hold on to their valence electrons very weakly. Think of them as positive ions (cations) floating in a sea of electrons Think of them as positive ions (cations) floating in a sea of electrons

A Sea of Electrons

Sea of Electrons Electrons are free to move through the solid. Electrons are free to move through the solid. Therefore Metals conduct electricity. Therefore Metals conduct electricity.

Metals are Malleable Can be hammered into shape (bendable) Can be hammered into shape (bendable) Also ductile - drawn into wires. Also ductile - drawn into wires. Both malleability and ductility are possible because of the mobility of the valence electrons Both malleability and ductility are possible because of the mobility of the valence electrons

Malleable Force

Malleable Mobile electrons allow atoms to slide by, sort of like ball bearings in oil. Mobile electrons allow atoms to slide by, sort of like ball bearings in oil. Force

Ionic solids are brittle Force

Ionic solids are brittle Strong Repulsion breaks a crystal apart, due to similar ions being next to each other. Strong Repulsion breaks a crystal apart, due to similar ions being next to each other. Force

Chemical Reaction A process in which one or more substances are converted into new substances with different physical and chemical properties A process in which one or more substances are converted into new substances with different physical and chemical properties Before reaction After reaction

Chemical Reaction Definition Reactant – Substances present before a chemical reaction Reactant – Substances present before a chemical reaction Product – Substances present after a chemical reaction Product – Substances present after a chemical reaction Therefore, a chemical reaction can be states as reactants changing into products Therefore, a chemical reaction can be states as reactants changing into products

Reasons for Reactions An atom with an incomplete set of valence electrons will bond. Atoms try to obtain a complete set of valence electrons and thus become more stable by reacting with other substances

States of Matter Solid, Liquid, Gas, Plasma Solid, Liquid, Gas, Plasma The movement (or lack of movement) of atoms results in different states of matter The movement (or lack of movement) of atoms results in different states of matter

States of Matter Solids- Solids- Atoms are in a fixed position, they vibrate but do not change position Atoms are in a fixed position, they vibrate but do not change position They have a definite size and shape They have a definite size and shape Liquids- Liquids- Molecules are close together and move freely Molecules are close together and move freely Takes the shape of its container Takes the shape of its container Gases- Gases- Molecules are freely moving and independent Molecules are freely moving and independent Completely fills its container Completely fills its container

Write down the properties of each state of matter!!!! A solid holds shape and has a fixed volume, a liquid……

Plasma Most of the matter in the universe is in the plasma state Most of the matter in the universe is in the plasma state Matter in this state is composed of ions and electrons Matter in this state is composed of ions and electrons Most electrons are found outside the electron cloud Most electrons are found outside the electron cloud Stars are composed of matter found in the plasma state Stars are composed of matter found in the plasma state

Phase Changes in Matter Factors determine state of matter Factors determine state of matter 1) Attraction between atoms 2) Rate of movement of atoms Temperature and pressure can affect these factors Increase temperature (SI Unit?)= Increase in movement Increase pressure = Decrease in space between atoms

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Physical Properties of Matter Can observe these with our senses! Density Density Color Color Smell Smell Hardness Hardness Melting Point Melting Point Boiling Point Boiling Point Ability to conduct electricity Ability to conduct electricity Magnetism Magnetism

physical change alters form or appearance of material, but does not change material into brand new substance alters form or appearance of material, but does not change material into brand new substance examples examples chopping wood chopping wood bending wire bending wire molding clay molding clay phase changes phase changes 59

Chemical Properties Are only observable during a chemical reaction paper burns paper burns iron rusts iron rusts gold does not rust gold does not rust wood rots wood rots nitrogen does not burn nitrogen does not burn silver does not react with water silver does not react with water sodium reacts with water sodium reacts with water

chemical properties observed only when substance is changed and interacts with another substance observed only when substance is changed and interacts with another substance examples examples flammability: able to burn flammability: able to burn rusting: combining with oxygen to form rust rusting: combining with oxygen to form rust 61