Atomic Structure and The Periodic Table

What is distillation?

A process that separates a pure liquid from a mixture of liquids

What is simple distillation?

Separate liquid from a solution- the liquid boils off and condenses into the condenser. The thermometer will read the boiling point of the pure liquid.

What is crystallisation?

Separating a solute from a solvent

What are the relative charges and masses of protons, neutrons and electrons ?

Charges - +1, 0, -1

Masses - 1, 1, very small

What is the plum pudding model ?

A sphere of positive charge with random negative electrons throughout it.

Equation for Rf

Height of pigment / height of solvent

What is an isotope?

Atoms of the same element with the same number of protons and electrons, but different number of neutrons

Equation for relative atomic mass (Ar)

(mass number X amount) + (for all isotopes) / total amount

How did the alpha particle scattering lead to a change in the plum pudding model ?

As when the positive charge hit the positive nucleus they repelled or get attracted to the electron or sometimes went through a gap meaning that the mass of the atom was mainly concentrated in the nucleus.

What are the characteristics of metals ?

• high melting and boiling points

• Thermal and electrical conductors

• High density

• Alkali

What are the characteristics of non-metals ?

• Low melting and boiling points

• Thermal and electrical conductors

• Low density

• Acidic

What are the characteristics of alkali metals ?

• Soft

• Low densities

• Low melting and boiling points

• Highly reactive

Why do all Group 1 elements show similar chemical reactions ?

They all have one electron in their outer shell

How do Group 1 metals react with water ?

React vigorously with water fizzing and moving around on the surface of water before melting

How does reactivity change going down Group 1 ?

Increases as the atoms get larger and the distance between the nucleus and the outer electrons increase and the attraction from the nucleus decreases, allowing them to lose more electrons easily.

What are the characteristics of Group 7 ?

• Coloured vapours

• Diatomic molecules

• Form ionic salts with metals

What are the changes that occur as you go down Group 7 ?

• Higher relative molecular mass

• Higher melting and boiling point

• Less reactive - less easily gain electrons

What is the rule for halogen displacement ?

A more reactive halogen will displace a less reactive halogen from an aqueous solution of its salt.

What happens to reactivity as you go down Group 7 ?

Reactivity decreases

Why does, in terms of electronic configuration, reactivity of halogens decrease down the group ?

• Atoms get larger

• Outer shell is further from nucleus and there is more shielding from the inner electrons

• Electrostatic attraction between nucleus and incoming electron weakens

• Electron is gained less easily

What are the characteristics of transition metals ?

• Form ions with different charges

• Form coloured compounds

• Catalysts without being used up

What are the properties of noble gases ?

• Extremely unreactive

• Non-metal

• Colourless gases

• Non-flammable

What is the trend in boiling points as you go down Group 0 ?

Increase as atoms get larger and have more electrons which increases the strength of the intermolecular forces between the atoms meaning more energy is required to break them apart.