chemistry of life Flashcards
(39 cards)
matter
what takes up space and has mass
element
smallest possible thing
cannot be broken down by a chemical reaction
what do compounds consist of
2 or more elements in a fixed ratio
who was the period table developed by
dimitri mendelevev
how many elements were there originatly in the periodic table
56
what are collums called
groups
how many % of elements are essential
20%
essential elements
C,H,O,N
what are atoms composed of
subatomic particles
neutrons
in nucleus
no charge
has weight
protons
in nucleus
+ charge
electrons
are in electrical charge
- charge
radiates around nucleus
atomic #
element identidy
isotopes
elements have same protons but diff nutrons
ionic bonding
when you transfer electrons
gaining electrons
- charge
loosing electrons
+charge
metals
group 1 and 2
usually bond
are givers
non metals
share electrons
double bond
when elements share more then one electrons
covelant bond
sharing a pair of valence electrons by 2 atoms
can form between atoms of same and diff element
2 types of valence electrons
polar and non polar
polar covalent bond
non equal
one atom will be pulling more and one will be pulling less
ex of a polar covalent bond
water
