PP Ch. 2 Flashcards
Why do electrons matter?
Whether an atom will interact with other atoms depends on how many electrons it has
What atoms are life’s chemical basis?
Protons, neutrons , electrons
How to electrons move around the nuclei?
They move in orbitals
What are the three most common types of bonds?
Ionic, covalent and hydrogen
What is an ionic bond?
Weak bond. Ions stay together because of mutual attraction of opposite charges, have a large difference in electronegativity
What is a covalent bond?
Two atoms with similar electronegativity and unpaired electrons sharing a pair of electrons. Stronger than ionic bond. Can share one, two or three pairs of electrons
What are the two types of covalent bonds and give a short explanation
- Non polar covalent bond : share electrons equally. Formed between atoms with identical electronegativity
- Polar covalent bond :
Atoms with different electronegativity do not share electrons equally. One atom is more neg other is more pos
What is polarity?
Separation of charge into distinct positive and negative regions in a polar covalent molecule
What is a hydrogen bond
A weak attraction between a highly electronegative atom and a hydrogen atom taking part in a seperate polar covalent bond. Not a chemical bond. Not a molecule. Stabilizes structures of proteins and DNA
Where did life originate ?
Life originated in water.
Does water have a charge?
No water does not have a charge
Is a water molecule polar or non polar? And why
Water molecule is polar because oxygen atom is slightly negative and hydrogen atom is slightly positive
Are polar molecules hydrophobic or hydrophilic?
Hydrophilic
Are non polar molecules hydrophilic or hydrophobic?
They’re hydrophobic
Are nonpolar molecules able to be dissolved by water?
No, only polar molecules
