Chemistry Of Life Flashcards
What is the atomic number?
The number of protons (above the chemical symbol)
What is the atomic mass?
The sum of the number of protons and neutrons
What are the masses of the proton, the neutron, and the electron?
Proton and Neutron: 1atomic mass
Electron: negligeable mass
Why is it that the atomic mass of most atoms isn’t an interger?
Because of their isomers, which makes them have more or less neutrons
What is a covalent bond?
It’s a bond in which two atoms share a pair of electrons.
What do you call a molecule made of more than one type of atom?
Compound
What is electronegativity?
The force that atoms exert on electrons.
What happens when an atom in a covalent bond has stronger electronegativity than the other atom?
The electrons shared in that bond will stay for a longer time close to the said atom.
Unequal sharing of electric charge.
What is called a covalent bond in which an atom is more electronegative than the other?
A polar covalent bond
What is the strongest bond in Bio 1?
Covalent bonds
What are hydrogen bonds?
- Positively charged portion of one molecule has a weak attraction to the negatively charged portion of another molecule (OH attracted to highly electronegative atom)
- H-bonds don’t share electrons
-Involve hydrogen with either oxygen, nitrogen, fluorine or chlorine
Why are H-bonds important for life?
Every being on Earth is held together by H-bonds
What are ionic bonds?
- A complete transfer of ele trons
What do atoms become when they lose or gain electrons? Be precise.
Ions:
- Cations if they lost electrons
- Anions if they gain electrons
What molecules are hydrophilic?
Polar molecules and ionic compounds
What molecules are hydrophobic?
Nonpolar molecules
What type of molecules usually dissolve in water? Why?
Ionic and polar molecules because of H-bonds