Periodic Table Flashcards
English scientist Robert Moseley arranged the periodic table according to what?
Increasing atomic numbers
Groups
Also called families or columns, top to bottom
4 characteristics of group 1 and 2 metals
1) Cannot be found alone on Earth
2) Appear in compounds as oxides
3) Lose electrons readily to react
4) Most active/reactive metals
Group 1
Alkali metals
Group 2
Alkaline earth metals
Group 17
Halogens
Group 18
Noble gases
Groups 3-12 and some under the staircase
Transition metals
Left of the staircase (except H2)
Metals
On the boldface staircase
Metalloids, semimetals, semiconductors
Right of the staircase
Nonmetals
Periods
Rows, left to right, related to the 7 PELS
Trends in a group - atomic radius
As atomic radius increases, atomic radius increases
Atomic radius
The size of an atom, from the nucleus to outermost electron
Electronegativity
The ability to attract electrons in a bond
4 facts about electronegativity
1) Fluorine has the highest EN of 4
2) Noble gases have an EN of 0
3) Metals have a low EN
4) Nonmetals have a high EN
Trends in a group - electronegativity
EN decreases as you go down a group
Ionization energy
The energy that must be added in order to remove the most loosely bound electron
Ionization creates a
Positive ion
Trends in a group - ionization energy
Ionization energy decreases going down a group, meaning it gets easier to remove the valence electron as you go down a column
Trends in a period - atomic radius AND WHY
Decreases going left to right because nuclear charge is decreasing, meaning electrons are pulled closer to the nucleus
Trends in a period - electronegativity
Increases going left to right
Trends in a period - ionization energy AND WHY
Increases going left to right, atomic radius is decreasing so it takes more energy to remove the valence electron closer to the nucleus
Trends in a period - metallic character
Decreases going left to right
