Chemistry 101 Flashcards
Why is chemistry important to biology?
life -> cells -> molecules -> atoms
What does the atomic number mean?
numbers of protons and number of electrons
How do you know how many neutrons there are?
mass number - atomic number
What are isotopes?
a different form of a single element when an element has different number of neutrons
What are four types of atoms that make up 96% of all living matter?
H, C, N, O
What can a periodic table tell you about electrons?
electrons exist at energy level and form shells around nucleus
When are atoms most stable?
when their valence shells are full
What is a cation?
losing electrons
What is an anion?
gaining electrons
What is electron transfer?
when an atom donates or gains electrons
What is the octet rule?
8 in outermost shell
What type of bonds do ions form?
ionic bonds
What is electronegativity?
ability of an atom to attract shared electrons
What does an atom with high electronegativity do?
- holds electrons more tightly
- has partial negative charge
- other atom partial positive charge
What is one of the most electronegative of all elements?
oxygen
