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The Periodic Table-Chapter 6 Organizing the elements A few elements, such as ______ and ________, have been known for thousands of years. Yet, only about ___ had been identified by the year 1700. As more were discovered, chemists realized they needed a way to _____________ the _____________. Mendeleev’s Periodic Table Chemists used the ____________ of elements to sort them into __________. By the mid-1800s, about ______ elements were known to exist Dmitri Mendeleev – a Russian __________ and ____________ arranged elements in order of ______________ __________ ________. Thus, the first __________ _________ was created. Moseley’s Periodic Table In 1913, Henry Moseley – A British physicist, arranged ___________ according to increasing _________ ___________ This is the arrangement used today The __________, __________ _________ & _________ are basic items included. The Periodic Law states: When elements are arranged in order of ________________atomic number, there is a periodic ____________of their physical and chemical ___________________. Horizontal rows = ____________ o There are ___ _________ Vertical column = _________ (or __________) o Similar ___________ & _____________ properties o Identified by __________ & ________ (IA, IIA) Areas of the Periodic table Three classes of elements are: ___________, _____________, and ____________ Metals: electrical conductors, have ________, are __________ and malleable Nonmetals: generally ________ and dull, poor conductors of heat and electricity. Metalloids: border the line-2 sides -1- Properties are intermediate between _____________ and _______________ Notice the heavy, _________-______ line? Remember: Many periodic tables are set up differently. Make sure to pay attention! Electron Configuration in Groups Elements can be sorted into 4 different groupings based on their ___________ ________________: 1. Representative Elements 2. ____________ __________ 3. __________ ________ 4. Inner transition metals 1) Representative Elements are in Groups 1A through 7A • They display wide range of ___________. • Their outer s and p electron configurations are __________ _________ or already full. 2) Transition metals are in the “B” columns of the periodic table • A __________ between the _______ area and the ____________ area. • Electron configuration has the outer s sublevel ______, and is now filling the “d” sublevel. 3) Noble gases are the elements in Group ___ ___ (also called Group 18) • Previously called “________ _________” because they rarely take part in a reaction; very stable = _______ _______. • Electron configuration that has the outer s and p sublevels ____________ ___________. The d sub levels may or may not be full. 4) Inner Transition Metals are located below the ______ body of the table, in _____ rows • Formerly called “______-_______” elements, but this is not always true because some are very abundant. • Electron configuration has the outer ____ sublevel full. The p and d ___________ may or may not be _______. The ____ ____________ is filling. -2- Elements in the 1A-7A groups are called the representative elements Group 1A are the __________ __________ (but NOT H) Group 2A are the __________ _________ ____________ Group 8A are the _________ __________ Group 7A are the _________ Trends in Atomic Radius First problem: Where do you start measuring from? The __________ ____________ doesn’t have a definite edge. They get around this by measuring more than 1 atom at a time. Atomic Size Measure the Atomic Radius - this is ________ the distance between the _______ nuclei of a diatomic molecule. -3- Atomic Size- Group Trends As we increase the atomic number or go down a group. . . each atom has another energy level, so the atoms get __________. Atomic Size-Period Trends Going from left to right across a ___________, the size gets __________. ____________ are in the same energy level. But, there is more nuclear charge. Outermost __________ are pulled closer to the atom’s nucleus. Ions An ion is an atom or group of atoms that has a ________ or _________ charge. Remember that atoms are neutral because the # of protons = # of electrons. Some compounds are composed of particles called ions. Positive and negative ions are formed when __________ are __________ (lost or gained) between atoms. Metals tend to LOSE electrons, from their outer energy level Sodium loses one: there are now more protons (11) than electrons (10), and thus a __________ charged particle is formed = “___________” The charge is written as a number followed by a plus sign: _________ Na1+ is re-named a “__________ ________” Nonmetals tend to GAIN one or more electrons • Chlorine will gain one _________ • Protons (17) no longer equals the electrons (18), so a charge of 1• _______________ ions are called “___________” • Cl1- is re-named a “chloride ion” -4- Ionization Energy Trends ________________ energy is the amount of energy required to completely remove an electron (from a gaseous atom). Removing one ______________ makes a 1+ ion. The energy required to _________ only the first __________ is called the first ionization energy. The second ionization energy is the energy required to remove the __________ __________. Always greater than first IE. And so on… Ionization Energy - Group Trends As you go down a group, the first ionization energy decreases because... The _____________ is further away from the attraction of the ____________. Ionization Energy - Period Trends All the atoms in the same period have the ________ __________ _________. Increasing nuclear charge So IE generally _____________from left to right. Exceptions at full and 1/2 full ____________. Driving Forces Full Energy Levels require lots of energy to ____________ their electrons. Noble Gases have _______ __________ __________. Atoms behave in ways to try and achieve a __________ ______ configuration. Trends in Ionic Size: Cations ____________ form by _________ electrons. Cations are __________ than the atom they came from – not only do they lose electrons, they lose an ____________ ___________ ____________. Metals form _________. Trends in Ionic size: Anions Anions form by _________ electrons. Anions are ___________ than the atom they came from – have the same ________ level, but a greater area the nuclear charge needs to cover ___________ form _________. -5- Electronegativity Trends _______________________ is the tendency for an atom to __________ electrons to itself when it is chemically combined with another______________. They ________ the electron, but how equally do they share it? An element with a big electronegativity means it pulls the ______________towards itself _____________! Electronegativity Trends-Groups The further _________ a group, the ____________ the electron is away from the _______________, plus the more electrons an atom has. This causes the electronegativity to ____________ as you go down the group. Electronegativity Trends-Periods Metals are on the _______ of the table. They let their ____________ go easily This causes electronegativity to be on the low side. On the ________ are the _______________. They want more ____________, so they try to take them away from others This causes electronegativity to ____________ as you go across the table. -6-