atomic structure and periodic table 😉🎀🎀🧪 Flashcards
what’s an isotope
same number of protons different number of neutrons
where is the atomic number
the bottom
what is relative atomic mass / mass number
number on the top
how to calc relative atomic mass
percentage X amount / 100
where are the metals and non metals on the periodic table
metals- left
non metals- right
groups
alkali metals
transition metals
halogens
noble gasses
what’s an alloy
mixture of different metals
what is a molecule
group of atoms chemically bonded together
what is a giant covalent structure and examples
molecules with many atoms
carbon
sulfur
different examples of carbon atoms bonded
diamond
graphite
what’s a compound
contains atoms of two or more different elements chemically bonded together
different types of compound
covalent
ionic
what type of bonding is ionic
metal and non mental ions
what type of bonding is covalent
all non metals bonding
where are electrons
in shells around nucleus
attraction to positively charged protons
how to find out number of electrons in an element
atomic number
J.J thompson
discovered electron
subatomic particles are evenly distributed in the atom
“plum pudding model”
john dalton
atoms weee first described as solid spheres
rutherford
alpha scattering experiment-mass concentrated at the centre. the nucleus is charged. most of the mass is in the nucleus,
most of the atom is empty space
bohr
electrons are in shells orbiting the nucleus
chadwick
discovered that there are neutrons in the nucleus
simple distillation
separating a liquid from a solution
fractional distillation
separating out a mixture of liquids
used to separate crude oil into fractions
halogens
non mental
go down- less reactive
go down-melting and boiling points become higher
noble gases
unreactive due to full outer shell
colourless gas at room temp
go down-boiling points increase
increase in number in electrons means greater intermolecular forces
development of periodic table
-arranged by atomic mass
-some elements hadnt been found so put in the wrong group
- mandeleev left gaps for undiscovered elements
-he put them in order of atomic mass
modern periodic table
-in order of atomic mass/proton number
-metals on the left non metals on the right
-group number shows electrons in outer shell
-predict the reactivity of metals
alkali metals
-soft and very reactive (one electron)
-low density
-go down- more reactive
-form ionic compounds with no metals
-react with water, chlorine and oxygen
mixtures
no chemical bonds
easy to separate
chromatography
to separate out mixtures
filtration
to separate solids from liquids
evaporation
to separate a soluble salt from a solution
crystallisation
to separate a soluble salt from a solution; slower method of separating a salt
separating out salt from rock salt practical
- grind mixture of rock salt
2.add water and stir - filter the mixture leaving the sand in the filter paper
4.evaporate the water from the salt, leaving the crystals
transition metals
-strong,shiny and good conductors or electricity and heat
-make good catalysts
-form more than one ion
usually coloured
-compounds also usually coloured
