Chemistry and Macromolecules Flashcards
(209 cards)
Of the 92 elements known, about__are required for organisms to survive.
¼
these elements make up >96% of living matter
C, H, O, P, S, N
Calcium, Phosphorus, potassium, sulphur, sodium, chlorine, magnesium
Trace elements
The discrete shells that electrons can occupy, have a specific capacity. The
closest shell can only hold___ electrons
2
The second shell can hold___ electrons
8
What does this image represent
Represents a probability map of where the electrons will be (not exactly orbiting nucleus)
Electrons try to____
Avoid each other and stay in their own zone
The properties of the atom are determined primarily by the number of______these are the_____
number of electrons in
the outermost shell, valence electrons
. Atoms with the _____of valence electrons behave _______
same number, similarly in chemical reactions.
An atom with
a____valence shell will be____
“full”, unreactive (inert).
The atomic number defines the number of_____ present in that particular element.
protons,
Because electrons are____, when an element is in its _____
it will have the same number of_____
negatively charged, neutral state, protons as electrons.
Every atom of boron contains___ protons
5
sharing of a pair of valence electrons by two atoms
Two or more atoms held together by____
covalent bonds = a molecule
Single pair of
electrons shared
Two pairs are shared
between two atoms:
= double bond
Covalent bonds can be_____
Nonpolar or Polar
Covalent bonds can be Nonpolar or Polar (determined by the_____of the atom, i.e., the________ of an atom for electrons of the other atom in the covalent bond).
electronegativity, attraction
strength,
Single bond, non polar
Double bond, polar, the electrons spend more time with the oxygen atom.
Dipole= separation of 2 opposite charges within the same molecule.
e.g., Carbon’s electrons would be dispersed in a “6-pointed structure, but
when bound to H, four pairs of electrons are shared and the s and p
orbitals rearrange to occupy 4 equidistant regions, which form a
tetrahedron
The formation of______ results in a rearrangement of,___________
Covalent Bonds, orbitals
in the valence shell.
When two atoms with a very different_____ the electron is transferred from______ leaving
the two atoms with a______ The oppositely charged_________ form an_____.
affinity for valence
electrons combine, one to the other, net change in their charge. cations and anions, ionic bond.