Chapter 2: Chemical Bonds Flashcards
What is a chemical bond?
An attractive force binding two atoms together, and the connected atoms are called a molecule
What is a covalent bond?
a type of chemical bond in which two atoms share electrons
What is the behavior of atoms based on?
How full the valence shell is with electrons
What is an atom’s valence?
how many electrons are needed to complete an atom’s valence shell
What is common about that atoms commonly present in living organisms?
they have incomplete valence shells
What are incomplete valence shells associated with?
highly reactive atoms
What do elements in the saw group/column have in common?
they have the same number of valence electrons
What does the number of covalent bonds an atom will make conform to?
Its valence! If an atom has a valence of 2, it will bond with 2 more atoms to make a molecule.
What is a functional group?
groups of atoms in a compound that determine the chemical behavior of the compound
ex: Carboxyl, Phosphate, Amino, Hydroxyl
What is electronegativity?
the ‘strength’ to which an atom pulls the shared electrons of a covalent bond towards itself
Why are atoms in a covalent bond sometimes shared unequally?
the relative differences in electro-negativity between the two atoms; the more electronegative atom will bring the electron closer to it more of the time
Equal Sharing of an Electron(s)
Nonpolar covalent bonds
Unequal sharing of an electron(s)
polar covalent bond
What results in partial negative and partial positive charges in different regions of a molecule?
The unequal pulling (electronegativities) of electrons between atoms in covalent bonds
What 2 things do electronegativities depend on?
- the number of protons in the nucleus
- the distance between the nucleus and the valence shell
More protons have a stronger electronegativity (smaller atoms), and more distance between the nucleus and valence shell has a weaker electronegativity.
