Question | Answer |
Many properties of the atoms are due to what? | distance of the outer electrons from the nucleus, and the effective nuclear charge experienced by these electrons |
What screen the outer electrons from the full charge of the nucleus? | core electrons |
Do electrons in the same shell screen each other? | not effectively at all |
What is the trend of effective nuclear charge as we move left to right across a period? | effective nuclear charge increases |
What is the trend of atomic radii as we go down a column? left to right? | atomic radii increases as we go down a column and decreases as we go left to right |
Are cations smaller or bigger than their parent atoms? | smaller |
Are anions smaller or bigger than their parent atoms? | bigger |
What is the size trend for ions of the same charge? | for ions of the same charge, size increases going down a column of the periodic table |
Isoelectronic series | a series of ions that has the ame number of electrons. Size decreases with increasing nuclear charge as the electrons are attracted more strongly to the nucleus |
ionization energy | the minimum energy needed to remove an electron from the atom in the gas phase, forming a cation. |
second ionization energy | the energy needed to remove a second electron. |
Why do ionization energies increase after all valence electrons have been removed? | because of much higher effective nuclear charge experienced by the core electrons. |
What are the trend of ionization energy as we go down a column? left to right? | first ionization energy decrease as we go down a column and increases as we go left to right. The smaller atoms have a higher first ionization energy. |
Electrons are first removed from where? | from the orbitals with the largest value of n |
Electrons are first added to where? | to orbitals wtih the lowest value of n |
electron affinity | energy change upon adding an electron to an atom in the gas phase, forming an anion. |
What does a negative electron affinity mean? positive? | the anion is stable if it is negative. anion is not stable if it is positive. |
What is the trend of electron affinities? | more negative as we go from left to right, little change as we go down column |
What elements have the most negative electron affinities?? | the halogens |
Is the electron affinities of the noble gases negative or positive? | all are positive |
What is the trend in metallic character? | increases as we go down a column, and decreases as we go from left to right |
characteristics of metals | good conductor of heat and electricity, luster, the metal atoms are oxidized to cations. |
Metal oxides + acids --> ? | salts and water |
are metal oxides basic or acidic? | basic |
nonmetal characteristics | lack luster, poor conductor of heat and electricity, gases at room temperature. Compounds of entirely nonmetals are molecular. Form anions when they react wtih metals. |
Are nonmetal oxides acidic or basic? | acidic |
Nonmetal + bases --> ? | salt and water |
Alkali metals | (group 1A), soft metals with low densities and low melting points. have the lowest ionization energies, so they are very reactive toward nonmetals. Form 1+ ions |
Alkaline earth metals | (group 2A), harder and more dense and have higher melting points than the alkali metals. Very reactive toward nonmetals. Form 2+ ions. |
Hydrogen | nonmetal, form molecular compounds w/other nonmetals, such as oxygen and halogens |
Oxygen | (in group 6A), diatomic molecule, gain electrons from other elements, thus oxidizing them. |
Ozone | O3 |
Halogens | (group 7A), nonmetals that exist as diatomic molecules, most negative affinities, form 1- ions. |
Noble gases | (group 8A), monoatomic gases, unreactive because they have completely filled s and p subshells. |
Do noble gases react at all? | only the heaviest noble gases are known to form compounds, and they do so only with very active nonmetals, like flourine |