Lecture One: Introduction Flashcards
How much of the world is water
71%
what are the 3 phases of water?
liquid, vapour, and solid
what compound is in 3 phases?
water is the only one naturally able to reside in 3 phases.
How did water come to earth , theory?
ice is on astroids, physicists think the earth was bombarded with astroids and mediators , this then melted on impact and created water on earth
what does an atom consist of?
nucleus, electron shell (cloud)
what is in the nucleus?
contains: protons (positive charge)
neutrons (no charge)
what does the electron shell contain?
Electron shell has electrons (negative charge)
electrons have what charge?
negative charge
protons have what charge?
positive
Do neutrons have a charge?
no
what is H?
hydrogen
what is O and C?
Oxygen and Carbon
whats an ion?
an atom or molecule that has a net electric charge, which has been made due to the gain or loss of an electron
can you gain and loose protons?
no never
which electrons are gained and lost?
ones in the outer most cell
whats Na+ ?
Sodium
whats Cl- ?
chloride
why does sodium have a positive charge?
?
whats explosive when exposed to water?
sodium
chlorine gas can do what to you?
kill you
sodium and chlorine make?
salt
what is S ?
sulphur
what is P?
phosphorus
whats K?
potassium
what happened in 1953?
basic form of DNA was being discovered
what happens in 2003?
mapping the human genome
whats the atomic number?
number of protons in the nucleus of an atom
Are noble gases reactive?
no
why are atoms allowed to ionise?
because of the atoms in the outer shell
what are the 3 types of bonds we need to know?
covalent, ionic, hydrogen bonds (weak)
covalent bonds involves what?
the sharing of electrons
In ionic bonding what happens?
one atom gain an electron, one atom uses an electron
what is eltrostatic attarction?
?
what do weak interactions do?
help stick molecules together
whats a common weak interaction?
hydrogen bonds
how long does a hydrogen bond last?
1 nano second
whats the relative strength of all bonds?
covalent is stronger then ionic, ionic is stronger then hydrogen
what the hardest bond to break?
covalent
when breaking a bond whats released?
energy
what are molecules made up of?
atoms
is water an ionic molecule?
no
what type of molecule is water?
a polar molecule
whats a polar molecule?
when one side is positively charged and one is negatively charged