plse help me with this

How are valance electrons involved in the formation of covalent bonds?

How do atoms in covalent bonds become slightly negative or slightly positive?

explain how attractions between molocules could cause water to have a higher boilling point that carbon dioxide.

In terms of electrons how is a covalent bond diffrent than an ionic bond.

thx a million

Sure! I'll explain each question one by one:

1. How are valence electrons involved in the formation of covalent bonds?
Covalent bonding occurs when atoms share valence electrons with each other. Valence electrons are the electrons in the outermost energy level (valence shell) of an atom. When two or more atoms come close together, their valence electrons interact and form shared electron pairs. These shared electron pairs are known as a covalent bond. The shared electrons create a stable arrangement for both atoms, allowing them to complete their valence shells.

2. How do atoms in covalent bonds become slightly negative or slightly positive?
In a covalent bond, the atoms involved may have different electronegativities. Electronegativity is the tendency of an atom to attract electrons towards itself in a chemical bond. If one atom is more electronegative than the other, it will attract the shared electrons more strongly, creating a partial negative charge (δ-) on that atom. The atom with lower electronegativity will have a partial positive charge (δ+) due to the electron imbalance. This uneven distribution of electron density creates a polarity within the molecule, resulting in slightly negative and slightly positive regions.

3. How attractions between molecules could cause water to have a higher boiling point than carbon dioxide?
The boiling point of a substance is determined by the strength of the intermolecular forces between its molecules. In the case of water, it has hydrogen bonding, which is a strong intermolecular force. Hydrogen bonding occurs when the hydrogen atom of one water molecule is attracted to the oxygen atom of a neighboring water molecule. These intermolecular attractions are relatively strong, requiring a greater amount of energy to break the hydrogen bonds and convert water from a liquid to a gas (boiling). On the other hand, carbon dioxide molecules are held together primarily by weak London dispersion forces, which are relatively weaker. Consequently, it requires less energy to break the intermolecular attractions in carbon dioxide, resulting in a lower boiling point compared to water.

4. In terms of electrons, how is a covalent bond different from an ionic bond?
In a covalent bond, atoms share electrons to achieve a stable electron configuration. Both atoms contribute electrons, and the shared electrons are localized between the bonding atoms. The atoms in a covalent bond do not lose or gain electrons entirely.

In contrast, an ionic bond involves the complete transfer of electrons from one atom to another. One atom donates electrons to become positively charged (cation) and another atom accepts those electrons to become negatively charged (anion). The resulting force of attraction between the oppositely charged ions forms an ionic bond.

Overall, covalent bonds involve the sharing of electrons, while ionic bonds involve the transfer of electrons between atoms.