Chapter 7 Chem 130
Why are the electron affinity values for the noble gases endothermic?
An electron added to a noble gas must go in the next higher energy level.
Alkaline earth metals reactivity
Beryllium does not react with water Magnesium only reacts with steam react readily with water increases as you go down a group
Where will the largest jump in ionization energies occur for aluminum?
Between the third and fourth ionization energies
Which element will release the most energy when gaining an electron? Chlorine Helium Sodium Carbon
Chlorine
Identify the largest ion. Cl- F- Na+ Li+
Cl-
Which element is the most metallic? Cs Mn Si O
Cs
Came to the same conclusion about how elements should be grouped
Dmitri Mendeleev and Lothar Meyer
The periodic trend for electron affinity values is not as consistent as for other trends. Which statement best describes the trend? -Electron affinity becomes more negative going from left to right but does not have a clear trend going from top to bottom for most columns. -Electron affinity becomes more negative going from top to bottom but does not have a clear trend going from left to right. -Electron affinity does not have a clear trend in either the rows or columns. -Electron affinity only has a trend in group 1A metals becoming more negative from top to bottom.
Electron affinity becomes more negative going from left to right but does not have a clear trend going from top to bottom for most columns.
discovered the nuclear atom
Ernest Rutherford
Which element has the least metallic character? F Si Na Cs
Flourine, F
Which element will react with these noble gases to form compounds? Fluorine Chlorine Sodium Sulfur
Fluorine
Group 7A
Halogens
Which element requires the most energy to lose one electron? Helium Fluorine Potassium Cesium
Helium
developed the concept of atomic number experimentally. The number of protons was considered the basis for the periodic property of elements
Henry Mosely
Which one of the following statements is true regarding ionization energies? -Ionization energies are all endothermic. -First ionization energies are exothermic, while second and successive ionization energies are endothermic. -Ionization energies are all exothermic. -Ionization energies for removing valence electrons are exothermic and endothermic for removing core electrons.
Ionization energies are all endothermic
Which element has the smallest ionization energy? K Ne Kr H
K
Which pair gives the more metallic element first? K, Li Ge, Ga B, Al Sn, Pb
K, Li
This person's table was based on atomic masses. It was the most fundamental property of elements known at the time.
Mendeleev's
Which sequence lists the ions in order of increasing radius (smallest to largest)? Mg2+ < Na+ < F− < O2− Na+ < Mg2+ < O2−< F− O2− < F− < Na+ < Mg2+ F− < O2− < Mg2+ < Na
Mg2+ < Na+ < F− < O2−
Which sequence lists the atoms in order of increasing atomic radius (smallest to largest)? O < C < Si < Al Li < Mg < Al < Ge B < C < N < O H < He < F < Ne
O < C < Si < A
Group 6A
O, S, Se are nonmetals Te is a metalloid Po is a metal
Group 6A
Oxygen Group
Which of the following elements has the largest atomic radius? Rb Xe Ne Li
Rb
Compare the outermost electron in each of the following atoms. Which one will experience the smallest effective nuclear charge? Sodium Potassium Calcium Beryllium
Sodium
Which one of the following has the smallest atomic radius? Sulfur Silicon Sodium Selenium
Sulfur
The outermost electron of boron experiences a lower effective nuclear charge than carbon. Why?
The nuclear charge increases from boron to carbon, but there is no additional shielding.
What factor causes the atomic radius to increase while moving down the periodic table, from top to bottom?
The number of electron shells increase.
effective nuclear charge formula
Z-S
Nonmetal oxides are...
acidic
Group 1A
alkali metals
soft metallic solids found only in compounds in nature metallic properties
alkali metals
Group 2A
alkaline earth metals
nonmetals form....
anions
Z
atomic number
Metal oxides tend to be...
basic
half the distance between nuclei in a bond
bonding atomic radius
metals form...
cations
hydrogen in acid compounds are...
covalent
Ionization energy __________ moving down the periodic table from top to bottom. In moving across the periodic table, from left to right, ionization energy __________.
decreases increases
ionic size ___________ with an ____________ nuclear charge
decreases increasing
Alkali metals show trends, such as electron affinity and melting point, that are not typically seen in other groups of metals. Moving from lithium to cesium, the melting point _____ and the electron affinity becomes _____.
decreases more positive
Atomic radius trend
decreases from left to right across a period increase from top to bottom of a group
What do I values depend on?
effective nuclear charge and average distance of the electron from the nucleus
the energy change accompanying the addition of an electron to a gaseous atom
electron affinity
what are flames caused by
electronic transitions
Why are anions larger than their parent atom?
electrons are added and repulsions between electrons are increased
alkali metal reactions with water are....
exothermic
electron affinity is typically...
exothermic (negative)
Smaller atoms have ___ ionization energies
higher
Properties of Alkali earth metals
higher densities and melting points than alkali metals ionization energies are low, but not as low as alkali metals
when hydrogen reacts with metals, what forms
hydride anions
Moving down the periodic table, from top to bottom, does the metallic character increase, decrease, or stay the same for the elements in the same column?
increases
Group 7A, the halogens, show periodic trends with respect to their melting point, boiling point, and density. As you move down the column, the melting and boiling points _____ and the density _____.
increases increases
For the outermost electron of an atom, effective nuclear charge _________________ as you go from left to right on the periodic table. This is because electron shielding _____________________, due to electrons being added to the same energy level as the outermost electron.
increases stays constant
First Ionization energy trend
increases across a period decreases down a group
Effective nuclear charge trend
increases across a period slightly increases down a group
what are the sizes of ions determined by?
interatomic distances in ionic compounds
compounds formed between metals and nonmetals are typically...
ionic
the minimum energy required to remove an electron from the ground state of a gaseous atom or ion
ionization energy
ions have the same number of electrons
isoelectric series
Noble gases
large ionization energies positive electron affinities relatively unreactive found as monoatomic gases
anions are ________ than their parental atoms
larger
Anions are _____ than their neutral parent atom, and cations are _____ than their neutral parent atom.
larger smaller
alkali metallic properties
low densities and melting points low ionization energies
electrical semiconductors
metalloid
substances containing only nonmetals are...
molecular compounds
Group 8A
noble gases
half of the shortest distance separating two nuclei during a collision of atoms
nonbonding atomic radius, or van der Waals
on the right side of the periodic table
nonmetal
Electron affinity trend
not much change in a group increases across a period 2A is full 5A is half full 8A is full
Electrons are attracted to the _____________ and repelled by ___________________________.
nucleus other electrons
lithium + oxygen
oxide
O2
oxygen gas (dioxygen)
Which pair lists the element with the lower first ionization energy first? Oxygen, fluorine Magnesium, calcium Chlorine, sulfur Helium, neon
oxygen, fluorine
O3
ozone gas
the repetitive pattern of a property for elements based on an atomic number
periodicity
sodium + oxygen
peroxide
S
screening constant
Properties of metals
shiny luster, conduct heat and electricity, malleable and ductile, solid at room temperature, low ionization energies/form cations easily
Cations are _______ than their parental atoms
smaller
properties of nonmetals
solid, liquid, or gas solids are dull, brittle, and poor conductors large negative electron affinity, so they form anions easily
K, Rb, Cs, + oxygen
superoxides
What does ionic size depend on?
the nuclear charge number of electrons orbitals in which electrons reside
Why are cations smaller than their parent atom?
the outermost electron is removed and repulsions between electrons are reduced
Halogens
typically nonmetals have highly negative electron affinities so they exist as anions in nature react with metals to form halides