Octet Rule and Electronegativity

Octet Rule and Electronegativity

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Multiple Choice

Cations have a __________ charge.

• positive

• negative

• neutral

Multiple Choice

Anions have a ________ charge.

• positve

• negative

• neutral

Octet Rule

• ›Atoms have the greatest stability (i.e. lowest energy) when they have 8 valence electrons

• ›Completely filled subshells

• ›No advantage to gaining or losing electrons

Octet Rule

• Atoms will gain or lose electrons to achieve a noble gas-like electron configuration

• They can also share electrons to achieve a stable octet

• 
  

Multiple Choice

How do atoms meet the octet rule?

• They lose or gain protons

• They lose or gain neutrons

• They lose or gain electrons in the outer most level

• They lose of gain electrons from the inner most level

Multiple Choice

According to the octet rule, atoms of elements react with each other in order to attain ____ electrons in their outermost energy level or shell.

• 2

• 4

• 6

• 8

• 10

We can write electron configurations for ions

Gain or lose the appropriate number of electrons

Predicting Ion Charges

• Metals typically lose electrons

• Nonmetals typically gain electrons

Multiple Choice

Which of the following elements GAINS 3 electrons in order to attain an octet?

• nitrogen

• lithium

• boron

• oxygen

• fluorine

Multiple Choice

Which of the following elements LOSES 2 electrons in order to attain an octet?

• lithium

• magnesium

• helium

• sulfur

• bromine

Multiple Choice

What is the typical ion charge that forms when phosphorus forms an ion?

• +1

• +2

• -1

• -2

• -3

Multiple Choice

Which of the following elements GAINS 1 electron in order to attain an octet?

• sodium

• calcium

• helium

• boron

• chlorine

Multiple Choice

What is the typical charge when potassium forms an ion?

• +1

• +2

• +3

• -1

• -2

Electronegativity

Another periodic trend

Electronegativity

• The tendency of an atom, when interacting with other atoms, to attract electrons to itself

Comparing electronegativity

• Most electronegative element: Fluorine

• Least electronegative element: Cesium and francium (tied)

• We typically don't report electronegativity values for the noble gases, as they generally don't form compounds

Electronegativity of the elements

Electronegativity increases from left to right across a period.

Multiple Choice

As you go from left to right across a period, electronegativity ____

• increases

• decreases

• remains the same

• varies randomly

Electronegativity of the elements

Electronegativity decreases as you go down a column.

Multiple Choice

As you go down a column, electronegativity ____

• increases

• decreases

• remains the same

• varies randomly

Multiple Choice

Atoms that have a high electronegativity, _______________.

• have a weak coulombic attraction between the nucleus and the outermost electrons

• have a strong coulombic attraction between the nucleus and the outermost electrons

• have more occupied energy levels.

• have a large atomic radius

Multiple Choice

Which of the following will have a higher electronegativity than arsenic (As)?

• Carbon (C)
• Neon (Ne)
• Antimony (Sb)
• Germanium (Ge)

Multiple Choice

Which has the greater electronegativity?

• H

• F

Multiple Choice

Which has the greater electronegativity:

N or C?

• C

• N

Multiple Choice

As you move across a period, the outer electrons are ________ to the nucleus, so the nucleus of the atom is ________ to attract electrons in a bond.

• closer, more able

• closer, less able

• further, less able

• further, more able

Multiple Select

Electronegativity trends follow the same pattern as:

• atomic radius trends

• ionization energy trends

• ionic radius trends

• density trends

Multiple Choice

Which element has a lower electronegativity value?

• Calcium

• Barium