Chemistry - Topic 1

Atoms

Atoms

The smallest part of matter.

Proton, Neutron and Electron

subatomic particles

Electrons

The smallest subatomic particle with a negative charge

Protons

The positive subatomic particle that is in the nucleus that contributes to atomic mass

Neutrons

The other subatomic particle with no charge that contributes to atomic mass

charge of an atom

Neutral, protons = electrons

number of elements in periodic table

118

Atomic number

number that goes up by one with each successive element on the periodic table

Mass number

number that tells the average amount of protons and neutrons in an element

Isotopes

Atoms with the same number of protons but different amount of neutrons, e.g Carbon - 14

electron shell maxiums

2, 8, 18 (8), 32

Valence shells/electrons

The outermost electron shell has the least electrostatic attraction to the nucleus

main categories in periodic table

Metals, metalloids, and non-metals

verticle GROUPS

The number of valence electrons of the elements, similar chemical properties

horizontal PERIODS

The number of electron shells

Group 18

Nobel gases, full valence shell

Group 1

Alkali metals, more reactive going down, 1 valence electron

Group 17

Halogens, more reactive going up, 7 valence electrons

Types of chemical bonding

Ionic bonding, metallic bonding, covalent bonding

Ions

Charged atoms that have either gained or lost electrons

Cation, positive charge

Ions that loose electrons

Anion, negative charge

Ions that gain electrons

Transition metals

Metals that have many different ions, e.g Iron (III)

Polyatomic ions

Non-metal ions that have combined to become a anion

Ionic bonding

Bonding that occurs between a non-metal and a metal, balancing ionic charges

Lattice

chemical structure of ionic compound

Ionic lattice pattern

Anions and cations alternating

Ionic lattice properties

hard, brittle, high melting and boiling points, crystalline solid, conducts electricity when not solid

Metallic bonding

Bonding between metals

Metal compounds are in a lattice of cations held together due to what

the delocalised electrons from the cations zooming around creating an electrostatic bond

metal compound properties

lustrous, high melting and boiling points, malleable and ductile, dense, good electrical and heat conductors

3 types of heat treatments on metals

quenching, annealing, tempering

annealing process

making a metal red hot and then cooling slowly

quenching process

making a metal red hot and then shocking it in ice water to cool it down

tempering process

quenched metals, reheated and then cooled slowly

tempering properties

less brittle/more malleable, retaining hardness due to a balance between crystal size and interconnectedness

quenching properties

harder, more brittle due to smaller crystals and larger gaps

annealing properties

softer, more ductile and malleable due to larger crystals with smaller gaps

solvent

the liquid a substance is dissolved into

solute

the dissolved substance that can be a liquid, solid, or gas

in displacement reactions what metals are displaced

the more reactive metal will displace the less reactive metal in the solution

when will a displacement reaction not occur

if the more reactive metal is already in the solution

what are the 3 methods of metal extraction

roasting in air, smelting, and electrolysis

covalent bonding atoms

non-metals

covalent bonds

a shared pair of electrons between non-metals

reactants

the substances before a chemical reaction

products

the substances formed during a chemical reaction

law of conservation of mass

reactants = products

acids

are molecular in structure

acidic solutions

have more H+ ions

basic solution

have more OH- ions

ph scale 0 - 7 - 14

acidic - neutral - basic

indicators

change colour at different ph values

strong acid names

hydrochloric acid, sulfuric acid, nitric acid

strong acids

are completely ionised

weak acids

incomplete ionisation, reversible reaction

molar (M)

concentration of solution

reaction of acids with reactive metals

acid + metal = salt + hydrogen

reaction of acids with metal hydroxides (neutralisation reaction)

acid + metal hydroxide = salt + water

reactions of acids with metal oxides

acid + metal oxide = salt + water

reactions of acids with metal carbonates

acid + metal carbonate = salt + carbon dioxide + water

reactions of acids with metal hydrogen carbonates

acid + metal hydrogen carbonate = salt + carbon dioxide + water

rate of reaction

how fast the reactants are converted into products

rate of reaction formula

-reactants/time or products/time

average rate of reaction

take a segment of the line and calculate the gradient

instantaneous rate of reaction

draw a tangent at the given point and then find gradient of tangent

collision theory requirements

collision, correct orientation, enough energy

activation energy

the amount of energy needed for a successful colllision

factors that can influence the rate of reaction

concentration, temperature, surface area, catalyst

greater concentration in a reaction

more frequent collisions, more successful collisions, faster rate of reaction

greater surface area in a reaction

more surface exposed to collisions, more frequent collisions, more successful collisions, faster rate of reaction

greater temperature in a reaction

increased kinetic energy, more particles with energy >Ea, more frequent collisions, more successful collisions, faster rate of reaction

catalyst in a reaction

lowers activation energy, more particles with energy >Ea, more successful collisions, faster rate of reaction

catalyst effect

weakens bonds within the reactants, does not contribute to the products