Chapter 4.1 / 4.2 Structure of an Atom OBJECTIVES Describe Dalton’s Atomic Theory.

1. Chapter 4.1 / 4.2 Structure of an Atom OBJECTIVES • Describe Dalton’s Atomic Theory. • Describe and illustrate the structure of an atom – define the subatomic particles of an atom

2. Structure of an Atom • Dalton’s Theory: all matter is made up of individual particles called ______________, which cannot be divided. • All ______________are composed of atoms • All atoms of the same element have the same mass, and atoms of different elements have different masses • ____________________ contain atoms of more than one element • In a particular compound, atoms of different elements always combine in the same way

3. Structure of an Atom • Atoms are made of subatomic particles: _____________, ____________ and____________ • _______________– neutral subatomic particle found in the nucleus of an atom • _____________– positively charged subatomic particle found in the nucleus of an atom • _____________– negatively charges subatomic particle found in the space outside the nucleus

4. Structure of an Atom • The ___________ charge of an atom is not evenly spread throughout the atom. • Positive charge is concentrated in a very small, ______________ area. • The __________________of the atomis a dense, positively charged mass located in the center of the atom.

5. Structure of an Atom • neutrons, protons and electrons can be distinguished by _____________, ____________, and ______________in the atom. • _________________: the number of protons in an atom of that element • Atoms of different elements have different ___________________________. • ___________________(atomic mass): sum of the _____________ and the _______________ in the nucleus of the atom

6. Structure of an Atom • ______________________: atoms of the same element that have different numbers of neutrons and different _____________ numbers • Isotopes of an element have the same _________________number but different _________________numbers because they have different numbers of neutrons

7. Chapter 4.3 Modern Atomic Theory OBJECTIVES • Describe Bohr’s model of the atom • Describe the electron cloud model

8. Modern Atomic Theory (4.3) • ___________________ Model of the Atom • A description of the ___________________of electrons in an atom • Electrons move with __________________ speed in ______________________ orbits around a nucleus (like planets around a sun)

9. Bohr Model Continued • Each electron in an atom has a specific amount of energy – _________________________________: the possible energies that electrons in an atom can have **An electron in an atom can move from one energy level to another when the atom ________________ or ___________________energy

10. Bohr’s Model of the Atom ________________ ____________gain or lose energy when they move between fixed energy levels ____________________ Bohr Model

11. Electron Cloud Model • ______________________________: a visual model of the most likely locations for electrons in an atom Scientists use the electron cloud model to describe the ___________________ locations of electron around the nucleus The_____________contains protons and neutrons The probability of finding an electron is higher in the _________________regions of the cloud. Electron Cloud Model

12. Electron Cloud Model • Atomic Orbitals • The electron cloud represents all the __________________________in an atom • ___________________________: a region of space around the nucleus where an electron is likely to be found

13. An electron cloud is a good ____________________ of how electrons ________________________ in their orbitals • Electron Configurations • ______________________________: the arrangement of electrons in the orbitals of an atom The most ________________________ electron configuration is the one in which the electrons are in orbitals with the ____________________________ possible energies.. When all the electrons in the atom have the lowest possible energies, the atom is in its _________________________________________.

14. Chapter 5.1 / 5.2 The Periodic Table OBJECTIVES • Describe the arrangement of elements in the modern periodic table. • Describe the general properties of metals, nonmetals and metalloids. • Describe how the properties of elements change across a period in the periodic table

15. Mendeleev’s Periodic Table • Mendeleev arranged the elements into rows in order of __________________ mass so that elements with ________________ properties were in the same ____________________ ______________________: is an arrangement of elements in columns, based on a set of properties that _________________ from row to row.

16. Modern Periodic Table • Mendeleev developed his periodic table before the discovery of protons – he did not know that all atoms of an element have the same number of protons • In the modern periodic table, elements are arranged by increasing atomic number (number of __________________________) ________________________: each row in the table of elements ________________________: each column on the periodic table

17. Properties of elements repeat in a ________________________ way when __________________ ___________________ are used to arrange elements into groups This pattern of repeating properties is the ____________________________ _____________________________is a value that depends on the distribution of an element’s isotopes in nature and the masses of those isotopes ____________________________– is defined as one twelfth mass of a carbon-12 atom

18. There are four pieces of information for each element ________________ __________________ __________________ _________________

19. The Periodic Law • Each row in the table of elements is a ________________________ • Each column in the periodic table is called a ______________________

20. Classes of Elements • Elements are classified as________________________, ___________________________, and ___________________________ _________________________________: are elements that are good _______________________________ of electric current and heat - except for mercury, metals are ___________________________ at room temp - most metals are __________________________ - most metals are __________________________ (they can be drawn into thin wires) ____________________________________ are elements that form a bridge between the elements on the left and right sides of the table

21. _____________________________ : are elements that are ____________________ conductors of heat and electric current - non-metals have _____________________________ points – many are gases at room temperature - all the ____________________ in the periodic table are non-metals ____________________________: are elements with properties that fall between those of metals and non-metals Across a period table, from left to right, the elements become ____________________ metallic and ________________ non-metallic in their properties

23. Chapter 5.3 Representative Groups (periodic table) OBJECTIVES 1. Identify the number of valence electrons in certain groups on the periodic table. 2. Predict the reactivity of some elements based on their location within a group.

24. REPRESENTATIVE GROUPS______________________Elements in a group have similar properties because they have the same number of ____________________________ electrons.___________________________: an electron that is in the highest occupied energy level of an atom - these electrons play a key role in chemical reactionsThe ___________________________are numbered 1-8 - this is the number of valence electrons in an electron configuration for the element in that group

25. ______________________♦the elements in Group 1A ♦ these metals have a single ___________ valence electron and are extremely reactive - they are only found as compounds in ________________ (example: NaCl - salt)♦the reactivity of alkali metals _________________ from the top of Group 1A to the bottom

26. ______________________♦ the elements in Group 2A♦ all alkali earth metals have ____________valence electrons♦ the differences in reactivity among the alkaline earth metals are shown by the ways they react with _______________________

27. ______________________♦ the elements in Group 3A♦ these elements have _____________ valence electrons♦ _____________________________ is the most abundant metal in the Earth’s crust

28. ______________________________♦ the elements in Group 4A♦ these elements have ______________ valence electrons♦ the metallic nature of the elements ___________________________ from top to bottom within the group♦ except for water, most of the compounds in the body contain _______________________________

29. _____________________♦ the elements in Group 5A♦ these elements have ________ valence electrons♦ includes elements with a wide range of physical properties♦ ______________________ and ___________________ are the most important elements in Group 5A

30. _____________________ • the elements in Group 6Athese elements have six __________ • valence electrons____________________ is the most abundant element in the Earth’s crust • complex form of life need oxygen to stay alive because oxygen is used to release stored energy in food • _________ was one of the first discovered elements discovered because it is found in large natural deposits

31. ______________________♦ the elements in Group 7a♦ these elements have _________valence electrons  highly reactive non-metals (fluorine and chlorine are the most reactive) – react easily with ___________________♦ despite their physical differences, the halogens have ___________________ chemical properties

32. ____________________♦ the elements in Group 8A♦ these elements have _________valence electrons except for helium (He) which has ____________♦ the noble gases are __________________ and ____________________ and extremely unreactive • When electric current is passed through the _________________ gases, they emit different colors • helium – pink krypton - white • neon – orange / red xenon - blue • argon – lavender