Electronegativity and Bond Types: Factors and Trends in Periodic Table

What is electronegativity?

The power of an atom to attract a pair of electrons in a covalent bond.

What type of bond is formed between elements with similar electronegativity?

A covalent bond.

What type of bond is formed between elements with very different electronegativity?

An ionic bond.

Which type of elements are generally more electronegative?

Non-metals.

What are the three factors affecting electronegativity?

Nuclear charge,

shielding, (outweighs others)

atomic radius.

How does nuclear charge affect electronegativity?

The more protons an element has, the greater the nuclear charge, leading to a stronger attraction between the nucleus and bonding pair of electrons.

Why does shielding affect electronegativity?

Electrons repel each other, and full electron shells shield bonding electrons from the attraction of the nucleus

MORE ELECTRON SHELLS, GREATER SHIELDING EFFECT

weakening attraction between nucleus and shared pairs of electrons in covalent bond

How does atomic radius influence electronegativity?

The further away shared pair of electrons are from the nucleus, the weaker the attraction to the nucleus, resulting in lower electronegativity.

EQ

Explain why atomic radius decreases across period

Same amount of electron shielding

Higher nuclear charge across period

Stronger attraction between nucleus and outer shell electrons

Outer shell electrons pulled closer to nucleus

Atomic radius decreases

EQ

Explain why atomic radius increases across group

Outer electrons further away from nucleus

More shielding overweighs increase in nuclear charge

Weaker attraction between nucleus and outer shell electrons

Outer shell electrons move further away from nucleus

What happens to electronegativity across a period?

Electronegativity increases across a period due to decreasing atomic radius so increasing nuclear charge but same level of electron shielding so greater attraction between nucleus and bonding pair of electrons

What happens to electronegativity down a group?

Electronegativity decreases down a group due to increasing atomic radius increasing nuclear charge and more electron shielding so less attraction between nucleus and bonding pair of electrons

What is the relationship between atomic radius and nuclear charge across a period?

Atomic radius decreases as nuclear charge increases, leading to stronger attraction between the nucleus and outer electrons.

How does the atomic radius change down a group?

The atomic radius increases down a group due to more electron shells and increased shielding.

What is the effect of shielding on atomic radius?

More shielding weakens the attraction between the nucleus and outer shell electrons, causing them to be held further away.

What is a polar covalent bond?

A bond where there is unequal sharing of electron density, resulting in partial charges on the atoms.

What does the dipole arrow in a polar bond indicate?

The direction of the dipole points toward the more electronegative atom.

How does electronegativity influence bond polarity?

Greater differences in electronegativity between two atoms result in more polar bonds.

What is the electronegativity of fluorine?

Fluorine has the highest electronegativity value of approximately 4.0.

What is the electronegativity trend in the periodic table?

Electronegativity increases from left to right across a period and decreases from top to bottom in a group.

What is the significance of the atomic radius in chemical bonding?

A smaller atomic radius leads to stronger attraction between the nucleus and bonding electrons.

What is the effect of increasing nuclear charge on electronegativity?

Increasing nuclear charge enhances the atom's ability to attract bonding electrons, increasing electronegativity.

What role does electron shielding play in chemical reactivity?

Increased shielding can decrease an atom's reactivity by weakening the attraction of the nucleus to bonding electrons.