Download PPTHANDOUTThe Modern Periodic Table

SCH3U Name: The Modern Periodic Table 1. An arrangement of the elements in order of their _________________numbers so that elements with _________________properties fall in the same column (or group). •Groups: vertical columns (#1-­‐18) •Periods: horizontal rows (# 1-­‐7) 2. Periodicity – the _________________ of the elements in the same group is explained by the arrangement of the _________________ around the nucleus. The s-­‐block Elements: 1. Group 1: Alkali metals -­‐ ns1 _________________silvery metals; most _________________of all metals, never found free in nature; reacts with _________________to form alkaline or basic solutions; stored under _________________; whenever you mix Li, Na, K, Rb, Cs, or Fr with water it will _________________ and produce an alkaline solution 2. Group2: Alkaline earth metals-­‐ ns2 _________________ reactive than Alkali, but still react in water to produce an _________________ solution; never found _________________ in nature; harder, denser, stronger than alkali; The d-­‐Block Elements: Transition Metals -­‐ Groups 3-­‐12-­‐ nd They are all _________________ with _________________ properties (malleability, luster, good conductors, etc…); are referred to as the _________________ and _________________ than alkali or alkaline; less _________________ than alkali or alkaline; for the most part their outermost electrons are in a d sublevel; exceptions to the electron configuration are found in these groups (Ex: Ni, Pd, Pt) The p – Block Elements: Groups 13 – 18 –np Contain _________________and _________________; _________________, along zigzag line, have characteristics of _________________ metals and nonmetals (many are _________________ conductors but are _________________). The metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium. Group 17 -­‐ Halogens – most reactive nonmetals-­‐np5 _________________electrons in outermost (s and p) energy levels (that is why so _________________ – only need one electron to have 8); called the _________________formers (they react vigorously with metals to form salts). A salt is a _________________ion and a _________________ion bonded together. Most are _________________. Group 18 -­‐ Noble gases –unreactive-­‐np6 _________________ electrons in outermost s and p energy levels; all are _________________. The f-­‐Block Elements: Inner Transition Metals _________________ electrons fill an f sublevel • Lanthanides – shiny _________________metals; Ce-­‐Lu (fill the 4f sublevel) • Actinides – _________________ and _________________; Th-­‐Lr (fill the 5f sublevel) Hydrogen and Helium -­‐ Oddballs • Hydrogen is NOT an Alkali metal; it is a very _________________ gas. It is placed with the Alkali metals because 1s1 is its electron configuration. • Helium is a Noble gas, it is _________________, but it does not have 8 electrons in outermost energy level, because it only has 2 total electrons! SCH3U Trend in Atomic Radii Name: Atomic Radius Atomic radius is the distance from the centre of the nucleus of an atom to the outermost electron. The size of an atomic radius cannot be measured exactly because it does not have a _________________ defined boundary. However the atomic radius can be thought of as _________________ the distance between the nuclei of identical atoms joined in a molecule. The greater the number of energy levels the _________________ is the distance of the outermost electron to the center of its atom’s nucleus. Group trend -­‐ atomic radii _________________ as you move up a group. Period trend – atomic radii _________________ as you move across a period. Ionic Radius Ionic radius is the distance from the centre of the nucleus of an _________________ to the outermost electron. Cations will have a _________________ ionic radius than the neutral atom. Anions will have a _________________ ionic radius than the neutral atom. Force of Attraction: The force of attraction between negatively charged electrons and the positively charged nucleus is the _________________ attraction of opposite charges. The force of attraction existing between the outermost electron and the middle of the nucleus is dependent on two factors: 1. The _________________ of the positive charge -­‐ determined by the number of protons in the nucleus. 2. The _________________ between the outermost electron and the nucleus. A balance exists between the _________________ of the electrons to the nucleus and the_____________ of the electrons between themselves Ionization Energy (IE) Ionization Energy is the energy in kilojoules per mole (kJ/mol) needed to _________________ the outermost electron from a gaseous atom to form a _________________ ion (cation). + -­‐ Na + Energy → Na + e
NOTE: Metals react to _________________ electrons. The stronger an electron is held the _________ the IE needed to ionize (pull away) that electron Trend: Ionization Energy (IE) Group trend – ionization energy _________________ as you move _________________ a group (or _________________ as you move _________________ a group). Period trend – Ionization energy _________________ as you move across the period ( left to right). Example: Which atom has the higher first ionization energy? Hf or Pt. Explain. Example: Which atom has the higher first ionization energy? Cl or Ar. Explain. SCH3U Name: Electron Affinity [EA] Electron affinity is the energy _________________ in kilojoules per mole (kJ/mol) when an electron is _________________ by an atom to form a _________________ ion (anion). Cl + Electron → Cl-­‐ + Energy NOTE: Nonmetals react to _________________ electrons Trend: Electron Affinity (EA) Period trend – electron affinity _________________ as you move across a Period because atoms become _________________and the nuclear charge _________________. This means there is a greater pull from the nucleus. Group trend – electron affinity _________________as you move _________________a group (or _________________as you move _________________ a group) because the size of the atom _________________. Example: Which element has the greater electron affinity? Pb or Sn. Explain Electron affinity vs. Ionization energy Electron affinity and Ionization energy follow the same trend in the periodic table. The ________________ the attraction an atom has for electrons the _________________ it will be to remove electrons from that atom and the _________________ the IE energy will be. The _________________ the attraction for electrons the _________________ the energy released when an atom gains an electron. Electronegativity [EN}
Electronegativity is a measure of the _________________ of an atom to gain electrons when it is chemically combined (bonded) to another element. The _________________ the ‘pull’ or attraction of electrons to an atoms nucleus, the _________________ its tendency to gain electrons. In general, metals have _________________ EN and nonmetals have _________________ EN. The actual amount of EN an atom has is indicated by a number of the Pauling Electronegativity Scale that goes from 0 to 4. Dr. Linus Pauling set up this scale and gave the element having the greatest EN an arbitrary number of 4, and he assigned numbers to the others relative to this element. Trend: Period trend -­‐ EN _________________ as you go across a period (excluding the noble gases) because size _________________. Group trend -­‐ EN _________________ as you go _________________ a group because there is _________________ pull from the nucleus as the electrons get further away. Example: Which would have the greater EN? Ca or Se. Explain. SCH3U Name: Electronegativity enables us to predict what _________________ of bond will be formed when two elements combine. Reactivity of Nonmetals Reactivity -­‐ how _________________ a substance reacts with another. •Metals lose electrons (Ionization Energy) •Nonmetals gain electrons (Electron Affinity) Trends: Group Trend: Period Trend: Element # of electrons # of valance electrons # of protons EFFECTIVE NUCLEAR CHARGE (ENC) AND SHIELDING Na Mg Al Si P S Cl Ar # of inner electrons ENC SCH3U Name: The force of attraction between _________________ charged protons in the nucleus and _______________ charged electrons is the force that holds atoms together. The inner electrons (not in the outermost energy level) in inner energy levels, partially _________________ or _________________ the attraction of the protons from the outer electrons in the outermost energy level (VALENCE ELECTRONS). The canceling of the positive nuclear charge is called __________ ___________. EFFECTIVE NUCLEAR CHARGE (ENC) is a number assigned to elements to describe the amount of shielding _________________ by the valence electrons. ENC = Number of _________________ -­‐ Number of _________________ electrons The greater the ENC the _________________ the valence electrons are shielded and the _______________ the pull on the valence electrons. Greater ENC will mean a _________________ atomic radius. Shielding will help explain some of the trends in the periodic table SUCCESSIVE IONIZATION ENERGIES The first ionization energy is the energy required to remove the _________________ electron (First IE). It is relatively low because of the repulsion exerted by the other electrons. Each successive Ionization energy (Second and Third IE and so on) will _________________. It becomes _________________difficult to remove successive electrons since the pull of the nucleus becomes _________________ (greater number of protons relative to the electrons) and the electrons are _________________tightly held Ionic radius becomes _________________. There will be a _________________ jump in the increase of IE once the _________________ gas configuration has been reached. This is because outer energy level has been _________________ (radius is smaller) Example 1: Consider the following Ionization Energies for an element X: How many valance electrons does this element have? Explain. 1st
2nd
3rd
4th
5th
2.38 kJ 2.54 kJ 22.48 kJ 25.88 kJ 28.35 kJ Example 2: Where would the large increase in I.E. occur for Se? Explain your answer. SCH3U Name: Periodic Table Trends Worksheet 4. Which main group elements have 1 valence electron? _____ 6 valence electrons?____ 5. Without looking at the periodic table determine the group, period, and block for the following elements: a. [Ne]3s1 block____ group____period____ b. [Ar]4s23d10 block____ group____period____
c. [Ar]4s23d104p2 block____ group____period____ d. [Kr]5s24d2 block____ group____period____ e. [Kr]5s24d10 block____ group____period____
6. Use their placement on the periodic table to arrange the following elements based on their size (atomic radii) from largest to smallest. a. Ca, Ge, Br, K, Kr b. Sr, Mg, Be, Ba, Ra c. F, Cl, Fr, Cs 7. Use their placement on the periodic table to arrange the following elements from highest ionization energy to lowest ionization energy. a. Ca, Ge, Br, K, Kr b. Sr, Mg, Be, Ba, Ra c. F, Cl, Fr, Cs 8. Use their placement on the periodic table to determine which of the following has a higher electron affinity. a. F or Sn b. Si or Y c. Fe or K d. Bi or N e. Ho or Br f. Rb or Cl 9. Use their placement on the periodic table to determine which of the following has a lower electronegativity. a. F or Sn b. Si or Y c. Fe or K d. Bi or N e. Ho or Br f. Rb or Cl 10. Use their placement on the periodic table to determine which of the following is smaller. a. Ca atom or Ca ion b. Cl atom or Cl ion c. N ion or O ion Mg ion or Sr ion 11. Which of the following has the most shielding? a. Br or F b. Al or Cl or neither c. Ca or Ra 12. When sodium becomes an ion _______electrons are _________(lost/gained). 13. When aluminum ionizes, ______ electrons are _______. Nitrogen ionizes and ______ electrons are _______. 14. An ion that has a charge of +2 with 20 protons is the ______ ion. It has _____ electrons and _____ neutrons. 15. The ion that has a -­‐3 charge with 19 electrons is _______ 16. The ion that has a +3 charge with 26 protons is ________. _______________________________________________________________________________________ 4. Alkali Metals, Group 16 5. a. s,1,3 b. d,12,4 c. p,14,4 d. d,4,5 e. d,12,5 6. a. K,Ca,Ge,Br,Krb. Ra,Ba,Sr,Mg,Be c. Fr,Cs,Cl,F 7. a. Kr,Br,Ge,Ca,K b. Be,Mg,Sr,Ba,Ra c. F,Cl,Cs,Fr 8. a. F b. Si c. Fe d. N e. Br f. Cl 9. a. Sn b. Y c. K d. Bi e. Ho f. Rb 10. a. Ca ion b. Cl atom c. O ion d. Mg ion 2+
3-­‐ 3+
11. a. Br b. neither c. Ra 12. 1, lost 13. 3, lost, 3, gained 14. Ca ,18,20 15. S 16. Fe