Periodic Table and Trends Flashcards
What are the columns of elements in the periodic table?
Groups
What are rows of elements in the periodic table?
Periods
A family of elements is the same as…
A group
A metal can be stretched into thin wire is…
Ductile
The ability to conduct electricity is a property of…
Metals
A metal that can be hammered into thin sheets because it is…
Malleable
A property of metals is ____ or shininess.
Luster
______ is the gradual wearing away of a metal due to a chemical reaction with water or elements in the atmosphere.
Corrosion
Elements that are ______ are located to the right of the zig-zag line in the periodic table.
Nonmetals
Elements that have the same properties as both, metals and nonmetals are…
Metalloids
______ are elements that tend to gain electrons in chemical reactions.
Nonmetals
Coulombic Attraction
The attraction between oppositely charged particles.
less distance, more attraction; more distance, less attraction
Number of protons + attractive force
Increased protons –> increased attractive force
Electrons are attracted to protons in a nucleus, but are repelled by electrons in the same atom.
Electron Repulsion
Ion
An atom that is negatively/positively charged, or neutral.
Valence electron
Electrons in the outermost shell of an atom.
How is an ion formed?
When an atom gains/loses an electron to reach stability
Ionization energy
Energy required to remove an electron
Ionic Radius
The size of an ion, when it gains/loses an electron.
Cation
Positively charged ion - neutral ion is larger than (>) +ion
Na+
- less electrons -> less repulsion
- # of shells dec. -> stronger attraction towards valence electrons
- less shielding effect
Anion
Negatively charged ion - neutral ion is smaller than ( more electron repulsion
- same shielding effect
Shielding Effect
Describes the balance between the pull of the protons on valence electrons and the repulsion forces from inner electrons
Atomic Radius
The size of an atom
- The distance between the nucleus and valence electrons
- 1/2 distance between the nuclei
Atomic Radius - across a period
Atomic radius DECREASES
- proton # increases, attraction increases
- distance stays the same -> same period = same # of shells
- shielding effect stays the same
- electron repulsion increases, but not as effective
Atomic Radius - down a group
Down a group, atomic radius increases
- distance between valence electrons and nucleus increases -> # of shells increase
- shielding effect increases, attraction decreases
- electron repulsion increases (makes atom larger)
Electronegativity
The tendency for an atom to attract shared electrons when forming a chemical bond.
- element with the highest electronegativity: F (Fluorine) (approx 3.98 or 4.0)
- G18 ARE NONMETALS - DO NOT ATTRACT
Electronegativity - across a period
- Across a period, increases
- Atoms get smaller
- Proton # increases, distance stays the same
- Attraction towards electrons increase
- Electronegativity increases
Electronegativity - down a group
- Down a group, electronegativity decreases
- Atoms are getting larger
- Attraction gets weaker
- Less attraction, towards electrons
- Electronegativity decreases
Reactivity
A measure of how readily a substance undergoes a chemical reaction
Reactivity: Metals - down a group
- Down a groups, reactivity increases for metals.
- Starts to form positive ions
- Wants to lose electrons
- Less force of attraction - valence electrons
- Less ionization energy -> easier to remove an electron
- Easier to react to other elements
Reactivity: Metals - across a period
- Across a period, reactivity decreases for metals.
- More attraction for valence electron
- More ionization energy -> harder to remove an electron
- Harder to react with other elements
- Most reactive metal: Francium
Reactivity: Nonmetals - down a group
- Down a group, reactivity decreases for nonmetals.
- Forms negative ions
- Wants to gain electrons
- Less attractions - valence electrons
- Less electronegativity
- Lower reactivity
Reactivity: Nonmetals - across a period
- Across a period, reactivity increases in nonmetals.
- More attraction for valence electrons
- More electronegativity
- Higher reactivity
- Most reactive NM: Chlorine
Alkali Metals
- GROUP 1, does not include hydrogen
- Shiny, soft, highly reactive metals
- DO NOT OCCUR NATURALLY
- Only have 1 valence electron
- Reactivity increases down the group
Alkaline Earth Metals
- GROUP 2
- Has 2 valence electrons
- Somewhat reactive metals, some of which occur naturally as free elements
- Reactivity increases down the group
Icosagens
- GROUP 3
- All have 3 valence electrons
- Called “poor metals” due to their low melting points + hardness
- Liquid at a larger range of temperature than any other element
Crystallogens
- GROUP 4
- A mix of metals, nometals, and metalloids
- All have 4 valence electrons
Pnictogens
- GROUP 5
- All have 5 valence electrons
- All solids, apart from nitrogen, are a mix of nonmetals, metalloids and metals
Chalcogens
- GROUP 6
- All have 6 valence electrons
- Form -2 ions when reacting w/ electropositive metals
Halogens
- GROUP 7
- Contains elements in all 3 states of matter
- All reactive nonmetals
- All form diatomic molecules
- Reactivity decreases down the group
Noble Gases
- All monoatomic, rarely form compounds
- Not very reactive -> already have a full valence electron shell
