C1 Particles and the Periodic Table

C1 Particles and the Periodic Table

 

Atom is the smallest unit of an element, all matter is composed of atoms, has a nucleus with protons and neutrons and electrons on its shells.

Molecule is the smallest physical unit of a chemical compound.

Physical changes do not change the chemical composition of a substance, e.g. change of state, change of shape. No bonds are broken but intermolecular forces between molecules are broken.

Chemical changes makes a new substance in that bonding happens. Atoms of the elements are rearranged.

Elements are composed of one single type of atoms with the same number of protons.

Compounds are two or more atoms bonded together.

Mixtures are congregation of two or more substances that do not bond together. The product of the random distribution of one substance through another without any chemical reaction, as distinct from a compound.

 

Atomic structure

An atom has a nucleus, containing protons and neutrons, and shells on which electrons form.

 

	Relative Charge	Relative mass
Protons	+1	1
Neutrons	0	1
Electrons	-1	negligible

 

Proton number/atomic number is the number of protons in an atom.

Nucleon number is the # of protons and neutrons in an atom.

Periodic table is arranged in ascending shells and valence electrons, etc. Noble gases do not react because they have no valency electrons, a full outer shell.

Isotopes are atoms of the same element with the same proton number but different # of neutrons.

Relative atomic mass Ar is a comparison of a mass of an element to an atom of carbon-12, and the relative atomic mass always equals the nucleon number on the periodic table.

Destruction oxidation

 

Metal oxides are basic and most non-metal oxides are acidic. If non-metal oxides are not acidic, they are neutral (such as pure water). Some oxides of metals can behave as acidic even though they are basic. They are called amphoteric oxides.

 

Some elements are metalloids, intermediate between metal and non metal.

 

Metals	Non-metals
Metallic sheen, glossy	Dull and light
High density	Low density
Good electrical and heat conductor	Poor conducter
Strong	Weak
Malleable	Brittle

 

Group # = # of valence electrons. 1-3 Metals, 4-8 non-metals.

 

G1 Alkali metals

 

Lithium, sodium and potassium are a collection of relatively soft metals that are solid at room temperature and reacts violently with water to form strong alkali solutions

 

Reactivity increases down the group because elements with more shells are less stable. Melting points and hardness of G1 metals decreases down the group.

 

They FFMM, Fizz Float Melt Move on water’s surface.

 

G7 Halogens

 

Halogen reactivity is highest at top of the group. Chlorine will displace every halogen below it. Chlorine is yellow-green, bromine is red, iodine is brown-black.

 

G8 Noble gases

They are unreactive and they are useful to provide an inert atmosphere, where reaction is not desired. I.e. Argon in lamps, and helium for filling balloons.

 

Transition metals
They are a collection of metals having high densities and melting points that form colorful compounds and often act as catalysts.