Chapter 10 Deck 2

Why do atoms form chemical bonds?

Atoms form chemical bonds because bonding lowers the systems potential energy, making the atoms more stable than they would be if they remained separate

What three interactions determine the potential energy between atoms?

Nucleus - Nucleus repulsion, electron - electron repulsion, nucleus - electron attraction

What type of bond forms between a metal and a nonmetal

Ionic

What type of bond forms between a nonmetal and a nonmetal

Covalent

What type of bond forms between a metal and a metal

Metallic

What happens to electrons in an ionic bond?

Electrons are transferred

What happens to electrons in an covalent bond?

Electrons are shared

What happens to electrons in an metallic bond?

electrons are pooled together in a “sea of electrons”

Why do metals usually form negative ions?

Metals have relatively low ionization energies, so they lose electrons easily, becoming positively charged cations

Why do nonmetals usually for negative ions?

Nonmetals have high electron affinities, making it favorable to gain electrons and become negatively charged anions

Why is sharing electrons favorable in covalent bonding?

because the shared electrons sit between the nuclei, lowering potential energy and attracting both nuclei at the same time

Where are shared electrons located in the most stable covalent bond?

Between the two nuclei. This position gives the lowest potential energy and therefore the greatest stability.

What is meant by the “sea of electrons” in metallic bonding?

Metal atoms release their valence electrons into a shared pool of delocalized electrons that move throughout the entire metal crystal.

Why are metals good conductors of electricity?

Because their delocalized electrons are free to move through the metal, carrying electric charge

Why are valence electrons the only electrons involved in bonding?

Because they are the outermost electrons and are held least tightly by the nucleus, making them available to be transferred or shared

How can you determine the number of valence electrons in a main-group element?

Loot at the elements group (column) on the periodic table. The group number tells you the number of valence electrons

What does a Lewis dot symbol represent?

The element symbol represents the nucleus and inner electrons, while the dots represent only the valence electrons

What is the main purpose of the Lewis structure?

They help predict:

molecular stability, bonding, shape, size, and polarity

According to Lewis Theory, why do atoms bond?

Atoms bond to achieve a more stable electron configuration with lower potential energy by transferring or sharing electrons

What is the octet rule?

Most atoms become more stable when they have eight valence electrons, giving them a noble gas-like configuration

Why does potassium form K+ ions instead of K2+?

Losing one electron gives potassium the same electron configuration as the noble gas argon. Losing a second electron would remove a core electron and requite much more energy

According to Coulomb’s law, what two factors make an ionic bond stronger?

1. Larger ionic charges

2. Smaller ionic radii ( shorter distance between ions)

Greater charge and shorter distance produce stronger electrostatic attraction and higher lattice energy

Why do ionic compounds usually have higher melting points than covalent compounds?

Because oppositely charged ions experience very strong electrostatic attractions that require much more energy to overcome than the intermolecular forces between most covalent molecules.

Why does increasing ionic charge increase lattice energy?

Larger charges produce stronger electrostatic attractions between the ions, releasing more energy when the crystal lattice forms