Periodicity Flashcards
How many valence electrons do Group 1 elements have?
“One”
Are Group 1 elements univalent, divalent, or trivalent?
“Univalent”
What kind of ions do Group 1 elements form?
“Positive ions”
Are Group 1 elements reactive or unreactive?
“Reactive”
Are the compounds that Group 1 elements form stable or unstable?
“Very stable”
What is the trend in melting point down group 1?
“The melting points decrease.”
What is the trend in boiling point down group 1?
“The boiling points decrease.”
What is the trend in density down group 1?
“The density increases.”
What is the trend in atomic radius down group 1?
“The atomic radius increases.”
What is the trend in ionic radius down group 1?
“The ionic radius increases.”
What are the Group 1 elements known as?
“Alkali metals”
Name 3 examples of alkali metals.
“Lithium
Do alkali metals have high or low reactivity?
“High reactivity”
What kind of compounds do alkali metals form?
“Very stable compounds”
What charge do ions of alkali metals have?
“Positively charged”
What is the valency of alkali metal ions?
“Univalent
What is the general formula for the oxides of group 1?
“R2O”
Are the oxides of group 1 acidic, alkaline, or neutral?
“Alkaline”
What is the general formula for the chlorides of group 1?
“RCl”
Are the chlorides of group 1 acidic, alkaline, or neutral?
“Neutral”
What happens to the reactivity of alkali metals as you go down the group?
“The reaction becomes increasingly vigorous on going down the group
What happens to the oxides of alkali metals when they dissolve in water?
“The oxides of alkali metals also dissolve in water to form very strong alkalis”
What happens when you heat trioxonitrate(V) salts of group 1 elements?
“On heating
Do group 1 elements form strong or weak alkalis?
“Strong alkalis”
What kind of ions do group 1 elements form?
“Positive ions”
Are group 1 elements good or poor reducing agents?
“Good reducing agents”
How does the reducing property change down group 1?
“The reducing property increases down the group.”
Are group 1 elements electronegative or electropositive?
“Electropositive”
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Answer
What is the general formula for the hydrides of group 1?
“RH”
Are the hydrides of group 1 acidic, alkaline, or neutral?
“Neutral”
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Answer
What is the trend in the nature of oxides down group 1?
“The oxides become more alkaline.”
How does the vigor of the reaction between Group 1 elements and water change as you move down the group?
“The reaction becomes increasingly vigorous.”
What is the trend in melting points in Group 1 elements as you go down the group?
“Melting points decrease.”
What is the trend in boiling points in Group 1 elements as you go down the group?
“Boiling points decrease.”
What is the trend in density in Group 1 elements as you go down the group?
“Density increases.”
What is the trend in atomic and ionic radii in Group 1 elements as you go down the group?
“Atomic and ionic radii increase.”
What is the general formula of the oxides of Group 1 elements?
“R2O”
What is the nature of the oxides of Group 1 elements?
“Alkaline”
What is the general formula of the chlorides of Group 1 elements?
“RCl”
What is the nature of the chlorides of Group 1 elements?
“Neutral”
What is the general formula of the hydrides of Group 1 elements?
“RH”
What is the nature of the hydrides of Group 1 elements?
“Neutral”
How does the alkaline nature of the oxides change as you move down Group 1?
“The oxides become more alkaline.”
Who was the first scientist to construct a Periodic Table?
“Mendeléev
How did Mendeléev arrange the elements?
“He arranged the elements in order of increasing relative atomic mass.”
What did Mendeléev predict about the Periodic Table?
“He predicted that there were undiscovered elements which could fill the gaps in his table and even predicted their possible properties.”
What discovery clarified that elements vary regularly with?
“The discovery of the electronic structure of the atoms clarified that elements vary regularly with their atomic number.”
What is the modern Periodic Law?
“The modern Periodic Law states that the properties of the elements are a periodic function of their atomic numbers.”
What is the atomic number?
“The atomic number is the number of protons in an atom.”
Why is the number of protons equal to the number of electrons in an atom?
“Because an atom is neutral.”
What are the vertical columns in the Periodic Table called?
“Groups”
How are groups numbered?
“From 0 to 7”
What do elements in the same group have in common?
“The same number of electrons in the outermost shell of their atoms (same number of valence electrons).”
What are the horizontal rows in the Periodic Table called?
“Periods”
How are periods numbered?
“From 1 to 7”
What do elements in the same period have in common?
“The same number of electron shells.”
Where are metals located on the Periodic Table?
“On the left side of the diagonal line.”
Where are non-metals located on the Periodic Table?
“On the right side of the diagonal line.”
Where are metalloids located on the Periodic Table?
“Along the boundary line dividing metals and non-metals.”
What is the s-block?
“Groups 1 and 2”
What kind of elements are in the s-block?
“Reactive alkali and alkali-earth metals”
What is the p-block?
“Groups 3 to 7 and 0”
What kind of elements are in the p-block?
“Elements change from moderately active metals in Group 3 to very active non-metals in Group 7 and unreactive noble gasses in Group 0.”
Where are transition elements located?
“Between Groups 2 and 3”
What is the d-block?
“The transition elements”
Why are transition elements called the d-block?
“Because they contain d electrons.”
Where are lanthanides and actinides located?
“Between Groups 2 and 3 in Periods 6 and 7”
What is the f-block?
“Lanthanides and actinides”
Why are lanthanides and actinides called the f-block elements?
“Because they contain f electrons.”
What are the lanthanides and the actinides also known as
“The inner transition elements”
What are the atomic properties that vary periodically?
“Atomic size
How is atomic radius measured?
“It is taken to be one-half the distance of closest approach between the nuclei of atoms in the elemental substance.”
How do atomic radii of elements in the same period change as atomic number increases?
“They decrease.”
How do atomic radii change down a group?
“They increase.”
Are ionic radii of positive ions smaller or larger than their corresponding atomic radii?
“Smaller”
Are ionic radii of negative ions smaller or larger than their corresponding atomic radii?
“Larger”
What is periodicity?
“The recurrence of similar phenomena at regular intervals.”
What properties of elements vary periodically?
“Melting and boiling points; electrical and thermal conductivities; ionization energies and electron affinities; electronegativities”
How do melting and boiling points change across a period?
“Generally
How do melting and boiling points change within a group?
“The melting and boiling points of metallic elements decrease down the group
How do electrical and thermal conductivities change across a period and down a group?
“These properties of elements decrease across the period and increase down the group.”
What is ionization energy?
“The energy required to remove a valence electron from an atom of the element to form an ion.”
How does ionization energy change across a period?
“Generally
How does ionization energy change down a group?
“Generally
What is electron affinity?
“The energy change that occurs when a gaseous atom acquires an electron to form a univalent negative ion.”
How does electron affinity change across a period?
“Generally
What is electronegativity?
“The power of the atom in a molecule to attract electrons.”
How does electronegativity change across a period?
“Electronegativities of elements increase across a period”
How does electronegativity change down a group
“but decrease down a group.”
What are the four groups of elements which show great similarity in their chemical properties?
“Group 1 elements or the alkali metals; Group 2 elements or the alkaline earth metals; Group 7 elements or the halogens; and Group 0 elements or the noble gases.”
What kind of ions do Group 1 elements form?
“Positively charged univalent ions”
What kind of ions do Group 2 elements form?
“Positively charged divalent ion”
What kind of ions do halogens form?
“Negatively charged univalent ions”
Why are noble gasses unreactive?
“This property is due to their stable duplet or octet structures.”
How do metallic and non-metallic properties change across a period?
“The metallic properties tend to decrease across each period
What kind of compounds and oxides do elements on the left of Period 3 form?
“Mainly ionic compounds and basic oxides”
What kind of compounds and oxides do elements on the right of Period 3 form?
“Covalent compounds and acidic oxides.”
Why do elements in the same group show similar properties?
“Because their atoms have the same number of valence electrons.”
What is group trend?
“A gradual change of property within a group”
What are the familiar elements in Group 1?
“Sodium and Potassium”
What kind of ions do group 1 elements form and why?
“Positive ions by donating electrons”
What are group 1 elements known as and why?
“The alkali metals
