Science chemical patterns

Atoms

basic building blocks of materials in life,

Atomic mass

weight of one atoms of an element

electron configurations

2 8 8 2, most times,

Valence elctrons

electrons in the outer shell

ions

charged atoms

Anion

a charged atom that has gained electrons, (more fat and is angry)

Cations

lose electrons becoming positive

Valency

charge of an ion

Groups

column of elements in the periodic table

periods

rows in the periodic table

Metal physical properties

lustrous, malleable, ductile, good conductors, high melting and boiling points

Non metals

Dull brittle, poor conductors, low boiling points,

Transition metals valency

can have multiple valences because of backfilling

Bonding

atoms coming together to get a full shell

3 types of bonding

metallic bonding (2 metals), ionic bonding (metal and non metal), Covalent bonding, ( between two non metals)

Metallic bonding

when metal loses outer shell, positively charged ions form a lattice structure, with negatively charged electrons forming a sea of electrons to move around, positive and negative charged ions bond and intermingle to make structure

Properties due to metallic bonding

good conductors of electricity, because of movement of particles, good at creating heat because as heat rises, structure can move move freely, passing on energy, also are malleable but held due to sea of electrons

Ionic bonding

Direct swap of valence electrons

Oclet rule

8 electrons in their valence shell

Electron transfer diagram

demonstrates the formulation of ionic compounds and change of valence electrons in 2 ions

Swap and drop method

used for swapping valences of electrons, only works for atoms with different starting valencies

Covalent bonding

when valence electrons are shared between 2 non metals

Lewis Dot diagram

use dots to represent valence electrons around an atomic symbol, valence electrons arranged in pairs

STEP 1: Recognise that the elements involved are two non-metals

STEP 2: Finding out their atomic number from the periodic table work out the electron configuration

STEP 3: work out how many electrons each non-metal needs to share with the other non-metal(s) to fill the outer shell

STEP 4: Work out how the non-metals could all share the required electrons

Working out covalent bonds

Single bonds

a single pair of electrons are shared

Double bond

2 pairs of electrons are shared

Rules for naming covalent compounds

Number prefixes are used, last element always aint in ide, first element has no name change,

Isotopes

atoms that have the same number of protons or electrons, but different number of neutrons

Relative Abundance

is the percentage of that isotope for a naturally occurring element

Atomic Mass Formula

(%Isotope x Mass isotope +…)/100

RAM Formula

(RIM x Abundance +RIM x Abundance+___)/100

Element

a pure substance containing 1 atom that can not be broken down further

Valency

the number of atoms of a particular element that is combined with one atom of another element to form a molecule