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Name ____________________________________Date___________________________Hr______________ Notes – Atoms & the Periodic Table/Ions and Isotopes What’s an atom? The smallest particle of matter that still has all of the properties and characteristics of __________________________________. A copper atom is the smallest particle of copper that still has all of the __________________________________. ________________________ – the perpetual movement of particles (jiggling atoms) named after Robert Brown (Scottish botanist). What does an atom look like? An atom is mostly empty space and contains what we call subatomic particles. They are _______________________________________________. The ________________________ are located in the Nucleus, which is at the center of the atom. The electrons are located _____________________________ in what we call the electron cloud. Each subatomic particle has its own defining characteristics. They are outlined in the following chart: Name Symbol Charge Rel Mass Location____ __________ e1- (negative) 1/1840 Electron Cloud __________ p+ 1+ (positive) 1 Nucleus __________ n 0 (no charge) 1 Nucleus Draw a model here: What’s a periodic table? The periodic table is where we find elements. It is organized like a ______________________. The elements are placed in specific places because of the way they ______________________. What does the Periodic Table tell us? Each box represents an element. Each box contains. . . 1. Atomic Number The smaller number with no _____________________ Represents/determines the number of protons and electrons present in a ______________________________ 1 increase from top to bottom and from ______________________ If the atomic number is 2, the atom has ____electrons and ____ protons If the atomic number is 10, that atoms has … o i.e. Potassium 39.098 K 19 o Potassium has ____protons and when neutral, ____ electrons. 2. Atomic Mass Number is the ___________________ with a decimal place and is measured in amu (atomic mass units) This number gives us the number of __________________ in an atom To find the number of neutrons, we have a simple formula: o __________________________________ 3. Chemical symbol some have ___________ letters – always capitalized some have two letters – first letter always capitalized, second letter is ____________________ some have three letters – these are all man-made and may get renamed some symbols are based on ___________________ o Ex) Aurum – gold – Au Ferrum – iron – Fe Any element with an atomic number greater than ____ is man-made (created in a lab) Why is there usually a decimal place in the atomic mass number? It is due to _________________________ Isotopes – atoms of the same element with the same # of ____________ but a different # of _____________ the mass number is an estimate of all of the possible isotopes of each element o example: C-12 has 6 neutrons, C-14 has 8 neutrons – C-12 is more often found in nature so the atomic mass of C is 12.011, which is closer to _________________________ How is the periodic table divided? Into Metals, Nonmetals and Metalloids or into Families and Periods (Rows/Columns). Types 1. _________________ are located to the left of the zigzag (exceptions: H and metalloids) properties include: o have _______________(shine) o can be stretched and shaped 2 o conduct ________________________ very well 2. Nonmetals are located to __________________ of the zigzag (exceptions: metalloids) Properties include: o ______________________ o poor conductors of heat and electricity 3. Metalloids/Semi-metals/Semi-conductors along the zigzag (B, Si, Ge, As, Sb, Te, Po) Properties include: o some ________________________________________________ o not as good of conductors as metals but ___________________ _________________________________________________________ Families Vs. Periods (Rows versus Columns) 1. Rows/Periods are called _____________________ are horizontal (side to side) elements in the same row/period _________ _________________________________________ there are ____ of them on the periodic table 2. Columns/Groups are called groups or ______________ are vertical (up and down) elements in the same group/family ________________________________ there are ____of them on the periodic table o Ex) Li, Na, K all have a similar ____________________ with water (H2O). They all create an explosion that releases hydrogen gas (H2). Therefore, they are stored with oil, not water. Elements in the same group/family have the same number of __________________electrons Valence electrons – the number of electrons in an atom’s _________________ energy level o Ex) argon (Ar) versus neon (Ne) Atoms want to achieve a filled outermost energy level – we call this an __________________ if the energy level contains 8 valence electrons. Are the groups named? Each family of elements group has its own name. 3 Families _______________________________ Group 1 elements (except H) Have ___ valence electron Are the most active metals Tend to react with ____________ elements (halogens) Alkaline Earth metals Group 2 elements Have _________________________ Less reactive than alkali metals but are still reactive Tend to react with ____________________________ Transition metals group 3-12 on periodic table those families that we ___________________________ Metals, but different from alkali or alkaline earth metals Most have ____________ valence electrons Includes mercury (Hg) – the only ___________metal at room temperature Halogens Group ________ elements Some are gases, Br is liquid, and some are __________________ Have 7 valence electrons Tend to react with __________________ elements (alkali metals) _____________________ _____________________ elements He has 2 valence electrons Ne, Ar, Kr, Xe, Rn all have 8 valence electrons Are ___________________ since they already achieved an “octet” Contribute to less than 1% of earth’s atmosphere o O2 (21%) and N2 (78%) contribute to most of the atmosphere. ***Rare-Earth Elements includes elements at __________________ of periodic table (periods 6 and 7) first row = lanthanoid series- tend ____________________________ second row = actinoid series – most are _________________ (transuranium elements) and _______________________ 4 Names and symbols You will become familiar with the most commonly used elements and their symbols Name ____________ Boron Calcium ____________ Chlorine Copper ____________ Symbol Al B Ca C Cl Cu He Hydrogen ____________ Nitrogen Oxygen ____________ Gold H Fe N O Na Au Bohr Model We can use the periodic table to draw Bohr Models. These are also referred to as ____________________________. In these models we represent the protons, neutrons, & all the electrons. We already know that _________and neutrons are located in the nucleus at the _________________. The electrons are located in the electron cloud in energy levels 1st level holds ____________ ___________ 3rd 18e 2n^2 Fill in the following diagram: 5 Lewis ( Dot) Diagrams: Electron dot diagrams are structures that show the valence electrons ____________________________ Valence electrons are the electrons in the outmost shell and can be determined by looking at ______________________ on the periodic table Groups IA—VIIIA o If an element is in group IA it has_____ electron in its valence shell. o If an element is in group VA, it has ____ electrons in the valence shell. To draw the diagram: o Write the ____________ down o Place dots around the symbol, one on ________________ and then begin to pair them Draw Lewis dot for the first 20 elements. o We use Lewis dot structures to look at the valence shell configuration because that is where the bonding of atoms takes place! Notes – Ions and Isotopes Why is there usually a decimal place in the atomic mass number? It is due to _____________________. Isotopes – o Remember: Protons and neutrons have a relative mass of _____, and electrons are ______, so e- ________________ __________________________ when determining the mass o Since most of the mass of the element is from __________ _______________________, changing the number of neutrons changes the ____________________________ To determine the atomic mass, scientists take an _____________ mass of __________ isotopes of that atom. This gives us decimal places. When identifying isotopes, the ________________________ is given. o The mass number is a _______________________________ o Example: Carbon-12 has a mass number of 12. How many protons does it have? Why? 6 How many electrons does it have? Why? How many neutrons does it have? Why? Carbon-14 has a mass number of ______ How many p+ does it have? How many e- does it have? How many neutrons does it have? Why? When scientists take the average of these masses to determine the _____________________, they also consider which is _______________________________ in nature. o C-12 is found more often in nature so the atomic mass of C is 12.011, which is closer to 12 than 14 ***** IN SUMMARY ***** ____________________ is a whole number and only for one isotope of that atom ____________________ has decimal places b/c it’s an average of the masses of all isotopes. _____________________ are atoms of the same kind (so they have the same # p+ and e-), but have different #s of neutrons. What happens if we don’t have the same number of p+ and e-? Then we no longer have a __________________ atom. o Neutral atoms have _________ CHARGE o They have the same number of ________________ particles as _________________ particles. (these cancel each other out!) Example: Oxygen has an atomic number of ________. A neutral atom of oxygen has _________________ So… +8 + -8 = 0 In order for an atom to not be neutral, the number of ________ changes, the numbers of ___________________ remain the same. We call this an ______________ o Ion Example: o Oxygen commonly has a -2 charge. o Oxygen always has ____________________ o +8 + -x = -2 o X = _________ o This means there are ______________ in an ion of oxygen. o Symbol= O2- or O-2 Example: o Boron commonly has a +3 charge. 7 o o o o o Boron always has ____________________________ Equation: ________________________ This means there are _____________________ in an ion of boron. Symbol: ______________ Example: o If an atom has 7 protons and 10 electrons, what is its charge? Negative ions are called ________________. Positive ions are called _________________. 8