Trends Across a Period Quiz

Periodic Trends Quiz

The modern periodic table shows the elements arranged in order of increasing atomic number.

v  Arranged in this manner, the elements show a periodic pattern in their properties.

v  This is why it’s called a Periodic table!

What this means is that certain groups of elements share similar physical & chemical properties. 

v  Periodically, as you run through the elements by increasing atomic number, you come across an element with similar properties to any element of your interest. 

v  This is similar to a calendar; as you run through the days by increasing number, you periodically come across a Monday, Wednesday, etc. 

These periodic trends are due to the atoms’ composition and their desire to have a full outer energy level.  Remember the octet rule: atoms desire to gain or lose e^- to achieve 8 valence e^- (to be like noble gases).

v  Metals typically give up their e^- (form positive ions) to be like the previous noble gas.

v  Nonmetals typically gain more e^- (form negative ions) to be like following noble gas.

Periodic Trends

1.      Atomic Radius: Radius of atom without regard to surrounding atoms.  (Size of the atom)

v  Left to right, atomic radius ______________.  The reason for this is _______________________

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v  Top to bottom, atomic radius ______________. The reason for this is _____________________

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2.      Ionic Radius: Radius of ion formed from atom.  (Did it gain or lose electrons?)

v  Left to right and top to bottom, ionic radius mostly follows the same trend as atomic radius (which should make sense – think about from where the ion comes).

v  Positive ions are ______________ than the uncharged atom. The reason for this is ___________

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v  Negative ions are ______________ than the uncharged atom. The reason for this is __________

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3.      Electron Affinity: Attraction an atom has for an extra e^-. (How much it wants to form a [-] ion.)

v  Left to right, electron affinity ______________.  The reason for this is ____________________

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v  Top to bottom, electron affinity ______________. The reason for this is ___________________

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4.      Ionization Energy: Energy needed to remove an e^- from atom. (Energy needed to form a [+] ion.)

v  Left to right, ionization energy ______________.  The reason for this is ___________________

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v  Top to bottom, electron affinity ______________. The reason for this is ___________________

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5.      Electronegativity: Tendency of an element to pull e^- toward itself in a bond. (Follows e^- affinity trend)

v  Left to right, electronegativity _______________.  The reason for this is ___________________

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v  Top to bottom, electronegativity _______________. The reason for this is _________________

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