Introduction to Matter Matter & Measurements

Transcription

1 Introduction to Matter Matter & Measurements BIOB111 CHEMISTRY & BIOCHEMISTRY Session 1

2 Key concepts: session 1 From this session you are expected to develop an understanding of the following concepts: Concept 1: Valid measurements Concept 2: Arrangement of subatomic particles within an atom Concept 3: Atoms are neutral Concept 4: Atomic number Concept 5: Mass number Concept 6: Isotopes Concept 7: Arrangement of the periodic table Concept 8: Number of electrons within the electron shells Concept 9: Position of the electron shells within an atom Concept 10: Properties of electron shells These concepts are covered in the Conceptual multiple choice questions of tutorial 1

3 Session Overview Part 1: Introduction to matter What is matter? How can matter change: chemical and physical change Small units of matter: atoms, compounds & molecules Using measurements to quantify matter Part 2: Atoms Arrangement of subatomic particles within atoms Electron shells Part 3: Each elements atoms are different Atomic mass scale: atomic number and mass number The periodic table of elements Metals vs non-metals

4 Part 1: Introduction to matter What is matter? How can matter change?: chemical and physical change Small units of matter: atoms, compounds & molecules Using measurement to quantify matter

5 What is matter? SCIENCE is the study of matter & what makes it work CHEMISTRY is the study of structure, properties & transformation of matter

6 Cake is made from: Sugar Flour Eggs Water Every compound is made up of multiple atoms e.g. Carbon, hydrogen, nitrogen Components of the cake contain many different molecules (groups of atoms) Atom Stoker 2014, Figure 3-1 p54

7 What is matter? Matter is anything that has mass & occupies space Matter is composed of atoms Matter can exist as either a solid, liquid or gas Stoker 2014, Figure 1-1 p3

8 The periodic table of elements All matter is made up of one or more type(s) of atoms Each element has atoms that are different from all of the other elements atoms Stoker 2014, Figure 3-13 p81

9 How can matter change?: chemical and physical change Physical change: Matter can be changed from one state to another e.g. from solid into liquid Hallmarks of physical change: No new substances are created The type of matter present before the physical change is the same as the matter present after physical change Changing the state of water via physical change

10 How can matter change?: chemical and physical change Chemical change: Matter can be changed from one substance into another substance via a chemical reaction Hallmarks of chemical change: One or more new substances are created The type of matter present before the chemical change is different from the matter present after the chemical change Changing original substance(s) into different substance(s) via chemical change Chemical reaction:

11 Small units of matter: atoms, compounds & molecules Stoker 2014, p11

12 Small units of matter: atoms, compounds & molecules Oxygen molecule O 2 O H 2 O O Water Molecule H H O Example ATOM F Atoms join together to form groups GROUP OF ATOMS = MOLECULE F F Fluorine Atom Molecule that contains more than one type of atom Carbon Dioxide compound CO 2 Example O O C Example COMPOUND Water Compound Example H 2 O H H O

13 Small units of matter: atoms, compounds & molecules MATTER Is made up of ATOMS F Fluorine Atom Contain three different types of SUBATOMIC PARTICLES Negatively charged subatomic particle, around the outside of the nucleus ELECTRON e - Positively charged subatomic particle in the nucleus Subatomic particle in the nucleus with a neutral charge PROTON p + NEUTRON n 0

14 Small units of matter: atoms, compounds & molecules Atoms Atoms are the smallest particles within matter Atoms are made up of subatomic particles What makes an oxygen atom different from a carbon atom? An oxygen atom has 16 subatomic particles, whereas carbon has 12 subatomic particles / / The atoms of each different element have a different number of subatomic particles

15 Small units of matter: atoms, compounds & molecules PROTON Has 1 positive charge p + NEUTRON Has NO charge, is neutral, does not repel or attract n 0 Stoker 2014, Figure 3-1 p54 ELECTRON Has 1 negative charge e - (magnitude equal to p + but opposite in sign)

16 Small units of matter: atoms, compounds & molecules Subatomic particle Proton p + Electron e - Neutron n 0 Location within atom Charge Mass Nucleus Positive (+) 1 amu Around the outside of the nucleus Negative (-) 0 amu Nucleus Nuetral 1 amu

17 Small units of matter: atoms, compounds & molecules Oxygen molecule O 2 O H 2 O O Water Molecule H H O Example ATOM F Atoms join together to form groups GROUP OF ATOMS = MOLECULE F F Fluorine Atom Molecule that contains more than one type of atom Carbon Dioxide compound CO 2 Example O O C Example COMPOUND Water Compound Example H 2 O H H O

18 Small units of matter: atoms, compounds & molecules Molecules Molecules are composed of 2 or more atoms joined together via chemical bonds The atoms within a molecule can either be from one type of element or two or more different elements

19 Small units of matter: atoms, compounds & molecules Compound A compound is a molecule that contains more than one type of atom, where the atoms are joined via chemical bonds E.g. H 2 O, CO 2

20 Small units of matter: atoms, compounds & molecules Water is a vital compound for the human body 50 to 65% of the average human body is made up of water (H 2 O) Water is needed to transfer components between cells that make up the human body

21 Small units of matter: atoms, compounds & molecules Element Elements are found in nature in the form of single atoms only or as molecules containing only 1 type of atom E.g. Fe, Zn, Cu, O 2, H 2, N 2 Elements & compounds are referred to as pure substances Oxygen molecule O 2 O O MOLECULE

22 Small units of matter: atoms, compounds & molecules Each element has a different type of atom Due to the atoms containing different numbers of subatomic particles (protons, neutrons and electrons) 1-Letter Symbols 2-Letter Symbols Symbols from Latin/Greek C carbon Ca calcium Na sodium (Natrium) H hydrogen Mg magnesium K potassium (Kalium) O oxygen Zn zinc Fe iron (Ferrum) N nitrogen Mn manganese Cu copper (Cuprum) I iodine Co cobalt Pb lead (Plumbum) S sulphur / sulfur Se selenium Hg mercury (Hydrargyrum) P phosphorus Cr chromium Sn tin (Stannum) F fluorine Cl chlorine Ag silver (Argentum)

23 Using measurements to quantify matter Accurate measurements are important to assess the structure & properties of matter A measurement must include a number followed by an appropriate unit to be valid Common types measurements made in the laboratory: Quantity Units of Measurements Mass kilogram kg Volume Cubic meter/litres Symbols m 3 /L Temperature Kelvin/Celsius K/ C Pressure Pascal Pa Concentration Molarity M Energy, work Joule J

24 Why is it that both the number and unit are important when measuring the amount of water in a dam?

25 Why is it that both the number and unit are important when measuring the amount of water in a dam? Both the number and unit are required to make the measurement meaningful: Litres of water in the Wivenhoe Dam Without the unit the number could represent anything: Without a number the unit has no position on its scale: Litres

26 Using measurements to quantify matter Scientific notion Ways of expressing measurements Standard / Decimal Notation: The expression of a number using a decimal point e.g Scientific notation: Useful for expressing very large or very small numbers more easily e.g x 10-2

27 Using measurements to quantify matter Scientific notion Changing 93,000, into scientific notation Move the decimal point so that the decimal point is placed behind the first whole number In this case the first whole number is 9 Count the number of places you had to move the decimal point In this case the number of places is 7 (exponent) New decimal point position Original decimal point position.. The exponent is positive because the number being converted into scientific notion is above 1

28 Using measurements to quantify matter Scientific notion Changing into scientific notation Move the decimal point so that the decimal point is placed in front of the first whole number In this case the first whole number is 3 Count the number of places you had to move the decimal point In this case the number of places is 6 (exponent) Original decimal point position New decimal point position.. The exponent is negative because the number being converted into scientific notion is below 1

29 The measurement expressed in scientific notation becomes? a) x 10 3 b) x 10 4 c) x 10 2 d) x 10 3

30 Summary- Part 1: Introduction to matter What is matter? Everything is made up of matter The smallest unit of matter is the atom How can matter change?: chemical and physical change Chemical reactions (chemical change) allows matter to change from one substance into another E.g. a chemical reaction where methane burns in the presence of oxygen forming carbon dioxide and water Physical change allows matter to change from one state to another E.g. an ice cube melting turning water from a solid to a liquid

31 Summary- Part 1: Introduction to matter Small units of matter: atoms, compounds & molecules Atoms come together to form groups A molecule is a group of atoms connected via chemical bonds The molecules can contain either one type of atom or multiple different types of atom A compound is a molecule that contains more than one different type of atom connected via chemical bonds Atoms are made up of subatomic particles: Protons Neutrons Electrons Using measurement to quantify matter For a measurement to be valid it must have both a number and unit e.g. 1 litre of water Scientific notation: 3.87 x 10-2 vs decimal notation:

32 Part 2: Atoms Arrangement of subatomic particles within atoms Electron shells

33 Arrangement of subatomic particles within atoms The word atom is an ancient Greek work that means undivided It was thought that atoms can not be divided into smaller components We now know this is not true: Atoms contains subatomic particles protons, neutrons and electrons The average atom is one about one billionth of 10 cm Your body contains about 7 billion billion billion atoms 98% of these atoms are replaced every year

34 Arrangement of subatomic particles within atoms Dalton s atomic theory All matter is made up of tiny particles called atoms Atoms are in constant motion All atoms of the same element are identical Atoms of any one element are different from those of any other element / / Atoms are never created nor destroyed during a chemical reaction only rearranged

35 Arrangement of subatomic particles within atoms MATTER Is made up of ATOMS F Fluorine Atom Contain three different types of SUBATOMIC PARTICLE Negatively charged subatomic particle, around the outside of the nucleus ELECTRON e - Positively charged subatomic particle in the nucleus Subatomic particle in the nucleus with a neutral charge PROTON p + NEUTRON n 0

36 Arrangement of subatomic particles within atoms PROTON Has 1 positive charge (P + ) Mass = x g = 1 atomic mass unit NEUTRON Has NO charge, is neutral, does not repel or attract Mass = x g = 1 atomic mass unit ELECTRON Has 1 negative charge (e - ) Mass = x g The electrons mass is so small that it doesn t count towards the atoms mass

37 Small units of matter: atoms, compounds & molecules Subatomic particle Proton p + Electron e - Neutron n 0 Location within atom Charge Mass Nucleus Positive (+) 1 amu Around the outside of the nucleus Negative (-) 0 amu Nucleus Nuetral 1 amu

38 Arrangement of subatomic particles within atoms The nucleus is at the centre of the atom Protons & neutrons are tightly packed together in the nucleus Electron shells Nucleus Electrons Orbit around the outside of the nucleus The negative charge of electrons is attracted to the positive charges of the protons in the nucleus Like charges attract Stoker 2014, Figure 3-1 p54

39 Electron shells Electron shell Electron shells contains a group of electrons with similar energies The group of electrons in the electron shell are positioned a certain distance away from the nucleus Electron shell 1: Shell that is closest to the nucleus First shell that is filled with electrons Contains a maximum of 2 electrons Nucleus Electron Proton Neutron Electron shell 1 Electron shell 2 Electron shell 2: Shell that is 2nd closest to the nucleus Filled with electrons after shell 1 is full of electrons Electron shell 3: Shell that is 3rd closest to the nucleus Filled with electrons after shell 2 is full of electrons Contains a maximum of 18 electrons Electron shell 3 Each shell can hold a different number of electrons 2n 2 = the maximum No. of electrons that can be placed onto a shell Sub in the shell number in place of n Shell 1 2 e -, shell 2 8 e -, shell 3 18 e -, shell 4 32 e -, and so on

40 Electron shells Electron shells closest to the nucleus contain electrons with the lowest energy Electrons have a high level of attraction to the protons Hence, the electrons need a low amount of energy to hold their position close to the nucleus Electron shells further away from the nucleus contain electrons with higher energies Electrons have a lower level of attraction to the protons Hence, the electrons need a higher amount of energy to hold their position further away from the nucleus

41 Electron shells Orbital: A position within an electron shell where a maximum of 2 electrons are held Electron orbital containing 1 electron Electron Proton Neutron Electron orbital containing 2 electrons Electron shell 1 has 1 orbital Electron shell 2 has 4 orbitals Nucleus Nucleus Each orbital within the electron shell must have one electron, before any of the orbital can have two electrons (paired electrons) Atom that contains 4 electrons in electron shell 2 Each electron is unpaired Atom that contains 8 electrons in electron shell 2 Each electron is paired

42 Participation+: What is participation+? BIOB111 CHEMISTRY & BIOCHEMISTRY

43 Participation+ What is Participation+? An exercise where students discuss questions which require critical thinking Done in pairs 2 questions that cover content essential to your understanding of the BIOB session When will Participation+ run? In every BIOB session of semester for on campus students At the conclusion of an important topic within the BIOB111 session What can Participation+ do for me? Allows students to interact with their peers and the lecturer while discussing science in an informal setting Confirm your understanding of subject matter Develop a structured approach to addressing written questions (will be in the BIOB exam)

44 The students said: Why Endeavour students like participation+ "Participation+ helped us to think about what we had learnt and cement ideas and concepts" "Participation+ was very useful as it helped me to understand the content more and I also retained more information "Participation+ clarified a lot of concepts which at first seemed complex and contained a lot of information"

45 Important points about Participation+ Participation+ is an interactive activity that is student centric Participation+ gives the students an opportunity to talk about what they ve learnt earlier in the session in an informal setting Conversation between students is the key to Participation+ Ask questions of your partner to help understand the question No right or wrong answers >>> students work towards a possible solution together

46 Participation+ Regime Step 1 Step 2 Step 3 Step 4 Lecturer introduces the first Participation+ question 2 to 3 minute conversation between student pairs Whole class discussion forum or conversation between the lecturer and pair of students Students attempt conceptual MCQs via Socrative related to the original Participation+ questions

47 Example question Key concept: chemical reactions What happens during a chemical reaction (hint: think about the reactants and products?) How do atom rearrangements facilitate the conversion of reactants into products? Is it possible for products to be converted back into reactants? Why/why not? G

48 Example Socrative question As part of Participation+ students answer conceptual MCQs in Socrative

49 Example Socrative question Students receive real-time feedback on their answers to questions in Socrative

50 Have a go at your first Participation+ question Key concept: electron arrangement What is an electron shell? What is the order that electron shells 1, 2 and 3 are are filled with electrons? Why? Does an electron positioned close to the nucleus have a higher or lower energy than an electron that is further away from the nucleus? Explain why. G

51 Attempt Socrative questions: 1 to 5 Google Socrative and go to the student login Room name: City name followed by 1 or 2 (e.g. PERTH1) 1 for 1 st session of the week and 2 for 2 nd session of the week

52 Summary- Part 2: Atoms Arrangement of subatomic particles within atoms The nucleus contains the protons (positive charge) and neutrons (neutral) The electrons are positioned around the outside of the nucleus in electron shells

53 Summary- Part 2: Atoms Electron shells Electron shell 1 is closest to the nucleus and is filled with electrons first, followed by shell 2 and then shell 3 (further away from the nucleus) The electrons in shells close to the nucleus have low energy, due to a high level of attraction to the nucleus The electrons in shells further away from the nucleus have high energy, due to a lower level of attraction to the nucleus Electron shells contain orbitals Each orbital can hold a maximum of 2 electrons

54 Part 3: Each elements atoms are different Atomic mass scale: atomic number and mass number The periodic table of elements Metals vs non-metals

55 Small units of matter: atoms, compounds & molecules Each element has a different type of atom Each elements atom contains different numbers of subatomic particles (protons, neutrons and electrons) Only difference between the atoms of each element 1-Letter Symbols 2-Letter Symbols Symbols from Latin/Greek C carbon Ca calcium Na sodium (Natrium) H hydrogen Mg magnesium K potassium (Kalium) O oxygen Zn zinc Fe iron (Ferrum) N nitrogen Mn manganese Cu copper (Cuprum) I iodine Co cobalt Pb lead (Plumbum) S sulphur / sulfur Se selenium Hg mercury (Hydrargyrum) P phosphorus Cr chromium Sn tin (Stannum) F fluorine Cl chlorine Ag silver (Argentum)

56 The periodic table of elements Stoker 2014, Figure 3-13 p81

57 The Periodic Table of Elements Stoker 2014, Figure 3-3 p63

58 Atomic mass scale: atomic number and mass number The atomic mass scale is used to determine how much mass atoms, compounds and molecules contain 1 atomic mass unit (amu) is defined as 1/12 th of the mass of the carbon-12 atom (contains 6 protons and 6 neutrons) An atom s atomic mass is equal to the mass of the atom s nucleus

59 Arrangement of subatomic particles within atoms PROTON Has 1 positive charge (P + ) Mass = x g = 1 atomic mass unit NEUTRON Has NO charge, is neutral, does not repel or attract Mass = x g = 1 atomic mass unit ELECTRON Has 1 negative charge (e - ) Mass = x g The electrons mass is so small that it doesn t count towards the atoms mass

60 Atomic mass scale: atomic number and mass number Each element on the periodic table has an atomic number (smaller number) and a mass number (larger number) Mass number = mass of the atom Number of subatomic particles in the nucleus = protons + neutrons Atomic number Number of protons in the nucleus Na Chemical symbol for sodium 8 O 16.00

61 Atomic mass scale: atomic number and mass number Each element has a different chemical symbol Atomic number = number of protons in the nucleus of the elements atoms Each element has a different number of protons Na has 11 protons, hence a atomic number of 11 e.g. Na for sodium Na Each element has a different mass (amount of subatomic particles in the nucleus) Na has 11 protons + 12 neutrons, hence a mass number of 23 Mass number = number of protons + number of neutrons in the nucleus of the elements atoms

62 Atomic mass scale: atomic number and mass number Electron Proton Neutrons 1. What is the atomic number for the atom on the left? Nucleus Electron shell 1 Electron shell 2 2. What is the mass number for the atom on the left? 3. What type of element is the atom? Hint: use the periodic table

63 Atomic mass scale: atomic number and mass number Nucleus Electron Proton Neutrons Electron shell 1 Electron shell 2 1. What is the atomic number for the atom on the left? 9 protons = atomic number of 9 2. What is the mass number for the atom on the left? 9 protons + 10 neutrons = mass number of What type of element is the atom? Fluorine Mass number is 19 Atomic number is 9 9 F 19.00

64 Atomic mass scale: atomic number and mass number Atoms are neutral Atoms have an equal number of positive and negatively charged subatomic particles, making them neutral No. of protons = No. of electrons in an atom Atomic number of the element atom is equal to both the number of protons and also the number of electrons 6 C Carbon atom = overall net zero charge 6 positive charges from the 6 protons are cancelled out by the 6 negative charges of the 6 electrons Atomic number = 6 = No. of protons = No. of electrons Mass number = 12 = No. of protons + No. of neutrons

65 Atomic mass scale: atomic number and mass number Isotopes Atoms of an element that have the same Atomic No. but a different Mass No. Difference in mass numbers between isomers is due to different numbers of neutrons in the nucleus Carbon 12 isotope Carbon 13 isotope Carbon 14 isotope Abundance in nature: % Abundance in nature: 1.07 % Abundance in nature: %

66 Key concept: sub-atomic particles What are the different groups of subatomic particles within a Carbon-12 atom? What is the charge of each different subatomic particle present in the Carbon-12 atom? What is the location of each different type of subatomic particle within the Carbon-12 atom?

67 Attempt Socrative questions: 6 to 9 Google Socrative and go to the student login Room name: City name followed by 1 or 2 (e.g. PERTH1) 1 for 1 st session of the week and 2 for 2 nd session of the week

68 Periodic Table of Elements The elements are arranged by increasing Atomic No. i.e. first element has an atomic number of 1 PERIOD is a single horizontal row within the periodic table There are 7 periods PERIODS GROUP is a vertical column of elements within the periodic table Groups contain elements with similar physical & chemical properties There are 8 groups of group A elements The groups are numbered on the top & are divided into A & B A Groups = Representative elements (main focus) G R O U P S B Groups = Transition elements

69 Metals vs Nonmetals BIOB Non-metal elements seen extensively in the course include: Oxygen (O), carbon (C), hydrogen (H) and nitrogen (N) Stoker 2014, p83

70 Metals vs non-metals Modified from Stoker 2014, p83

71 Metals vs non-metals Adapted from Stoker 2014, Table 3-3 p66 Stoker 2014, Figure 1-9 p13 METALS NON-METALS Shiny solid substances at room temperature (except Hg!) Good conductors of heat & electricity Malleable Typical metals: Na, Cu, Au, Ag, Fe Metal atoms donate electrons (to a nonmetal) when forming an ionic compound Dull, not shiny, - solid, liquid or gas Poor conductors of heat & electricity (except Carbon) good insulators Not malleable Typical non-metals: H, C, O, N, S, P Non-metal atoms accept electrons (from a metal) when forming an ionic compound NOBLE GASES: Neither donate nor accept electrons, as their atoms are already stable

72 Attempt Socrative questions: 10 Google Socrative and go to the student login Room name: City name followed by 1 or 2 (e.g. PERTH1) 1 for 1 st session of the week and 2 for 2 nd session of the week

73 Summary Part 3: Each elements atoms are different Atomic mass scale: atomic number and mass number Atomic mass is used to quantify the mass of atoms, molecules and compounds The mass of 1 proton is 1 atomic mass unit, the mass of 1 neutron is one atomic mass unit The atomic mass of an atom is called the mass number The mass number is equal to the number of protons + neutrons in the atom s nucleus The atomic number is the number of protons in the nucleus of an atom Each element has a different number of protons in its nucleus

74 Summary Part 3: Each elements atoms are different The periodic table of elements The periodic table is a catalogue of all the known elements Each element has an atoms that contain different numbers of subatomic particles The representative elements are in group A of the periodic table The non-representative elements are in group B of the periodic table The groups of the periodic table are the vertical columns The periods of the periodic table are the horizontal rows

75 Summary Part 3: Each elements atoms are different Metals vs non-metals The elements on the periodic table can be divided into metal and non-metals In general the non-metal atoms are located at the top right of the table, whereas the majority of the other elements are metals (except hydrogen)

76 Readings & Resources Stoker, HS 2014, General, Organic and Biological Chemistry, 7 th edn, Brooks/Cole, Cengage Learning, Belmont, CA. Stoker, HS 2004, General, Organic and Biological Chemistry, 3 rd edn, Houghton Mifflin, Boston, MA. Timberlake, KC 2013, General, organic, and biological chemistry: structures of life, 4 th edn, Pearson, Boston, MA. Alberts, B, Johnson, A, Lewis, J, Raff, M, Roberts, K & Walter P 2008, Molecular biology of the cell, 5 th edn, Garland Science, New York. Berg, JM, Tymoczko, JL & Stryer, L 2012, Biochemistry, 7 th edn, W.H. Freeman, New York. Dominiczak, MH 2007, Flesh and bones of metabolism, Elsevier Mosby, Edinburgh. Tortora, GJ & Derrickson, B 2014, Principles of Anatomy and Physiology, 14 th edn, John Wiley & Sons, Hoboken, NJ. Tortora, GJ & Grabowski, SR 2003, Principles of Anatomy and Physiology, 10 th edn, John Wiley & Sons, New York, NY.

77 COMMONWEALTH OF AUSTRALIA Copyright Regulations 1969 WARNING This material has been reproduced and communicated to you by or on behalf of the Endeavour College of Natural Health pursuant to Part VB of the Copyright Act 1968 (the Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice.

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