Chemistry Chapter 6
Examine your graph of ionization energy (IE) vs. atomic number. Which elements are found at the main peaks on your graph (there should be 3)? What do these elements have in common?
He, Ne, Ar. These elements are all noble gases
Examine your graph of atomic radius verses atomic number. Which elements are found in the valleys on your graph? What do these elements have in common?
He, Ne, Ar. They are all noble gases.
What is ionization energy?
Ionization energy is the energy needed to take an electron from an atom.
The electron configuration of a chlorine atom is [Ne]3s23p5. When it gains an electron and becomes an ion, its electron configuration changes to [Ne]3s23p6, or [Ar], the electron configuration for argon. Has the chlorine atom changed to an argon atom? Explain.
It has not because even though the chlorine atom has the same number of electrons as Argon, it still has 17 protons which is what defines an atom.
One of the transition groups is often called the coinage group because at one time many coins were made of these metals. Which group is this? What element in this group is still used in many U.S. coins today?
It is group 11 and the element that is still used in many U.S. coins today is copper (Cu).
The law of octaves
John Newlands, chemical properties repeated every 8th element. did not work for all known elements
Examine your graph of ionization energy (IE) vs atomic number. Which elements are found at the main valleys on your graph (there should be 3)? What do these elements have in common?
Li, Na, K. These elements have low ionization energy, are part of group 1, typically form positive ions and have one valence electron.
Examine your graph of atomic radius verses atomic number. Which elements are found at the peaks on your graph? What do these elements have in common?
Li, Na, K. They all have one valence electron
Which element has the larger ionization energy? A. Li, N, Kr B. Ne, Cs, Li
N, Ne
Given any two elements within a group, is the element with the larger atomic number likely to have a larger or smaller atomic radius than the other element?
The element with the larger atomic number of two elements within a group will likely have a larger atomic radius because they have more energy levels than the element with the smaller atomic number and therefore the electrons are farther away from the nucleus and the pull is not as strong.
Of the elements magnesium, calcium, and barium, which forms the ion with the largest radius? The smallest? What periodic trend explains this?
The ion with the largest of radius is Barium. The smallest is Magnesium. The period trend that explains this is the trend of ionic radius and how as you move down a group on the periodic table, the ionic radius increases because the atom gains an energy level.
Which chemical family would be least reactive (least likely to bond with others) and why?
The noble gases (group 18) because they have a full outermost energy level and therefore no desire to gain or lose electrons.
Explain the octet rule. Why are hydrogen and helium exceptions to the octet rule?
The octet rule is that atoms lose or gain electrons so that they can have a stable electron configuration with 8 valence electrons. Hydrogen and helium are exceptions because they are stable and satisfied with ony 2 valence electrons.
Explain why the s-block of the periodic table is two groups wide, the p-block is six groups wide, and the d-block is ten groups wide.
The s-block of the periodic table is two groups wide because in an s orbital only 2 electrons can fit. The p-block is six groups because the p orbitals can hold a maximum of 6 electrons. The d-block has ten because d-orbitals can have 10 electrons.
Why do the elements chlorine, used in laundry bleach, and iodine, a nutrient added to table salt, have similar chemical properties?
They have similar chemical properties because they are both part of group 17 and are both nonmetals.
inner transition metals
a type of group B elements that are contained in the f-block of the periodic table and characterized by a filled outermost orbital and filled or partially filled 4f and 5f orbitals. divided in lanthanide and actinide series
groups/families
a vertical column of elements in the periodic table arranged in order of increasing atomic number
Rank each set of ions in order of decreasing size. a) K+, S2-, Cl- b) Au+, Au3+
a) S2-, Cl-, K+ b) Au+, Au3+
Rank the elements in each of the following groups of elements in order for decreasing first ionization energy: a) Sb, Te, Sn b) Li, K, Rb c) I, Xe, Cs
a) Te, Sb, Sn b) Li, K Rb c) I, Xe, Cs
what is the trend of ionic radius going left to right on the periodic table? why??
decreases until group 14, then increases suddenly and begins decreasing again. gets smaller because there are more protons to pull on more electrons. then the ions start gaining electrons and therefore an energy level instead of losing one so there are more electrons than protons and the electrons are not as strongly pulled to the nucleus and it begins to decrease again.
what is the trend of atomic radius moving left to right on the periodic table? why?
decreases, the more protons there are, the stronger the pull on electrons, makes atoms smaller
what is the trend of electronegativity going down the periodic table? why?
decreasing, electrons are farther away from the nucleus and it makes it harder to hold onto electrons
what is the trend of ionization energy going down the periodic table? why?
decreasing, the more energy levels, the farther electrons are from the nucleus and the harder it is for atoms to hold onto electrons.
_________ determines chemical properties
electron configuration
representative elements
elements from groups 1,2, and 13-18 in modern periodic table, possessing a wide range of chemical and physical properties
transition elements
elements in groups 3-12 and are further divided into transition metals and inner transition metals
metals
elements that are generally shiny when smooth and clean, solid at room temperature, and good conductors of heat and electricity
Dmitri Mendeleev
elements were ordered by increasing atomic mass, period pattern. predicted properties in undiscovered elements
metalloids
elements with physical and chemical properties of metals AND nonmetals
noble gases
extremely unreactive nonmetals, group 18
lanthanide series
f-block elements from period 6 that follows lanthanum
actinide series
f-block elements from period 7 that follow actinium
d-block
filled outermost orbital of energy level n and filled or partially filled d orbital of n-1 energy level, 10 groups
alkali metals
group 1 elements, not hydrogen, reactive, usually exist as compounds with other elements
alkaline earth metals
group 2 elements in the modern periodic table, highly reactive
s-block
groups 1 and 2 and Helium
p-block
groups 13-18, no period 1, group 18 = special, six groups
transition metals
groups 3-12, contained in d-block, filled outermost s orbital of energy level n and filled or partially filled d orbitals of n-1
halogens
highly reactive nonmetals, group 17
periods
horizontal row of elements in period table
what is the trend of atomic radius moving up to down the periodic table? why?
increases, electrons in higher energy levels are farther from the nucleus and inner electrons shield the nucleus from the outer electrons
what is the trend of ionic radius going down the periodic table? why?
increasing, atoms gain energy levels and are farther away from nucleus
what is the trend of electronegativity going left to right on the periodic table? why?
increasing, more protons and therefore the pull on electrons from other atoms increases, atoms on right side of periodic table want to gain electrons rather than lose
what is the trend of ionization energy going left to right on the periodic table? why?
increasing, more protons causes a tighter hold on electrons, as you move across periodic table, more valence electrons and therefore atoms want more and more to gain electrons rather than losing them
electronegativity
indicates the relative ability of an element's atoms to attract electrons in a chemical bond. noble gases do not have this. "desire to gain electrons to form a bond."
f-block
inner transition metals, filled or partially filled outermost s orbital and filled or partially filled 4f and 5f orbitals, spans 14 columns
What pattern do you notice as you move across OR down the table when considering valence electrons?
moving across, the number of valence electrons increases. moving down, the number of valence electrons stays the same.
Lothar Meyer
the connection between atomic mass and properties
ionization energy
the energy required to remove an electron from a gaseous atom, "energy cost to lose an electron"
Explain how an atom's valence electron configuration determines its place in the periodic table.
An atom's valence electron configuration determines its place in the periodic table because the groups are organized by the number of valence electrons an atom has. Also, the periodic table is sorted into the different types of energy levels (s, p, d, f) and so their location is based on how many energy levels an atom has.
Which element in each pair is more electronegative? A. K, As B. N, Sb C. Sr, Be
As, N, Be
Generally, as you go from left to right across a period on the periodic table, what happens to atomic radius? What about IE?
Atomic radius decreases, ionic radius increases
Generally, as you go down a group in the periodic table, what happens to atomic radius and IE? Why does that make it easier to lose an outer electron.
Atomic radius increases, ionization energy decreases. Because as atomic radius increases the electrons are farther from the nucleus and have less pull from the protons.
Explain why each successive ionization of an electron requires a greater amount of energy.
Because there are less electrons left to shield the remaining electrons from the nucleus and therefore the nucleus attraction increases.
what is biggerr? K+ or Cl-?
Cl-
Define electronegativity. Where on the periodic table is it highest? Explain why this is the case.
Electronegativity is an atoms want to gain electrons in an ionic bond. It is highest in the upper right corner because the elements there want to gain electrons to form bonds and they also have less energy levels and a stronger pull from the nucleus so its harder to lose electrons as well.
Give the chemical symbol for each element. A. the element in period 3 that can be used in making computer chips because it is a metalloid B. the group 13, period 5 metal used in making flat screens for televisions C. element used as a filament in lightbulbs; has the highest atomic mass of the natural elements in group 6
Si, In, W
How are atomic radii and ionization energy related (i. e. as atomic radius increases, what happens to the ionization energy)?
They are related because the elements with the most ionization energy have the smallest atomic radii and vice versa. Also ionization energy decreases rapidly and atomic radii increases rapidly.
Convert the following mass measurements as indicated. A. 1.1 cm to meters B. 76.2 pm to millimeters C. 11 mg to kilograms D. 7.23 μg to kilograms
a. 1.1 x 10^-2 m = .011 m b. 7.62 x 10^-8 mm c. 1.1 x 10^-5 kg d. 7.23 x 10^-9 kg
ion
an atom or bonded group of atoms with a positive or negative charge loses or gains electrons
Henry Moseley
atoms have specific number of protons based on element. arranged by number
octet rule
atoms lose, gain or share electrons in order to acquire the stable electron configuration of a noble gas
why do atoms in the same group have similar chemical properties?
they have the same number of valence electrons
nonmetals
upper-right side of the periodic table. gases or brittle, dull solids. poor conductors of heat and electricity. Bromine is the only nonmetal that is liquid at room temperature
What are valence electrons and why are they so important for understanding chemistry?
valence electrons are the electrons on an atoms outermost energy level and they are important to chemistry because the determine the type of ionic bond an atom forms and the ionization energy and electronegativity as well as where they are located on the periodic table.
period law
when the element are arranged by increasing atomic number, there is a period repetition of their properties
what elements are metalloids?
• 5 above the staircase (B, Si, As, Te, At) • 3 below staircase (Ge, Sb, Po)
