(P1) atomic structure/periodic table

what is the top and bottom number on elements

• mass number = top

• atomic number = bottom

what is group 0,1 and 7 called

0- noble gases

1-alkali metals

7- halogens

where are the groups on the periodic table

whats a mixture

• two or more substances not chemically joined together

methods which separate mixtures

• filtration

• evaporation

• distillation

how does filtration work

how does crystallisation work

how does fractional distillation work

how paper chromatography works

timeline for atom discovery

1. dalton

2. jj thompson

3. rutherford

4. bohr

daltons atom model

SOLID SPHERE

• atoms are solid spheres

• no electrons

JJ thomsons atom model

PLUM PUDDING

• discovered the electron

• atoms are positive spheres with negative electrons within

• atoms are divisible

rutherford’s experiment

ALPHA SCATTERING

1. fired alpha particles at gold foil

2. most went through—> atoms are mostly empty space

3. some deflected→ dense and positive nucleus

4. a few deflected—> nucleus holds most of mass

rutherford’s atom model

NUCLEAR MODEL

• tiny nucleus containing positive charge

• electrons move around the nucleus

Bohr’s discovery

ELECTRON SHELLS

• electrons orbit in fixed energy shells—> explains spectral lines

Chadwick’s discovery

NEUTRON DISCOVERY

• neutron is a neutral particle in the nucleus—> explains missing mass in atoms

subatomic particles charge, relative mass + location

the _____ electrons are from the nucleus, the more energy it has

• further away

how many electrons each shell can fill

first→ 2

second→ 8

third→ 8

why did Mendeleev have gaps in his periodic table

• some elements did not fit the pattern of atomic weight

how Mendeleev arranged the periodic table

• vertical columns based on their properties

why Mendeleevs table was never 100% accurate

• isotopes were uknown in his time

which elements lose elcetroms and gain electrons

metals lose electrons to form +ions

non-metals gain to form -ions

which side of metals on the periodic table have little electrons to remove

• left side

as you go down the groups of metals, what happens?

• the outer shell electrons get further away from the nucleus (weakens their attraction)

which have more outer electrons, non-metals or metals

non-metals—> easier to gain electrons to obtain a full outer shell

metals bonding + characteristics

• metallic bonding due to loss of electrons

• good conductors

• high melting/boiling point

• can be bent/shaped

non metals bonding + characteristics

• covalent from sharing outer electrons

• bad conductor

• low melting/boiling point

• brittle

key rule about non-metals and metals properties

they’re inversely proportional

as you go down group 0 _____ increases

• (HALOGENS)

• melting/boiling point

what do group 1 elements form when reacted with water

• (ALKLALI METALS)

• alkaline solutions

group 1 properties

• very soft

• low melting points

• VERY REACTIVE

as you go down group ____ the melting point decreases

• group 1 (alkali metals)

what are the group 7 elements called + are

• HALOGENS + non metals

what happens as you go down group 7

• HALOGENS

• melting/boiling point increases

what increases melting point

• strong intermolecular forces as more energy is needed to overcome them

what elements are used in medicine and specifically what

• transition metals are used in joint replacement

how are transition metals used in industrial usage

• form coloured compounds in paints for houses

• creating stained glass