Chemistry Y11 Topic 1

Democritus proposed atoms when?

460 BC

Meaning of greek word "atom"?

Indivisible

Dalton's model description

Solid spheres

What did Dalton say on compounds

Different atoms join

Who discovered electrons?

J.J. Thomson

Year electron discovered?

1897

Thomson's model name

Plum pudding

Plum pudding positive charge?

Spread throughout

Rutherford experiment used?

Alpha particles fired at gold sheet

Rutherford experiment key observation

Large deflections of alpha particles

Rutherford conclusion on atoms based on observation

Mostly empty space

Bohr added what?

Fixed energy levels added

Schrödinger model idea?

Probability clouds

Regions likely to find electrons called?

Orbitals

Why did the atomic models change?

New evidence provided over time

Atoms are what?

Building blocks of matter

All elements made of?

Atoms

Proton charge and mass?

+1, mass 1

Neutron charge and mass?

0, mass 1

Electron charge and mass?

-1, 1/1836

Atomic number definition?

Number of protons

Mass number definition?

Protons + neutrons

Protons and neutrons found?

Nucleus

Electrons found in? ( not orbital the other one )

Shells

Periodic table elements arranged by?

By order of Atomic number

Why atom neutral?

Number of protons = electrons

First shell max electrons?

2

Second shell max electrons?

8

Third shell max electrons?

18

Outer shells hold more because?

Higher energy levels and bigger radii

Define ion?

Atom that has Gained/lost electrons

Define cation?

Positive ion

Define anion?

Negative ion

Why do atoms form ions?

To get a full outer shell and become stable

Define isotope?

Same number of protons, diff neutrons

Why do some atoms have the same chemical properties?

Same number of electrons

Why diff physical properties in isotopes?

Different mass

Radioisotope stability?

Unstable isotope

Industrial isotope use?

Paper thickness

Dobereiner grouping?

Triads

Newlands pattern?

Law of Octaves

Newlands arranged by?

Atomic mass

Why Newlands rejected?

Groupings didn't match chemical properties

Mendeleev arranged by?

Atomic mass

Mendeleev table special feature?

Left gaps

Element Mendeleev predicted?

Gallium

Who used atomic number?

Henry Moseley

Year atomic number proposal?

1913

Iodine issue in the Periodic Table solved how?

Proton number arranged it correctly

Atoms in the same group share?

Same number of valence electrons

Atoms in the same periods share?

Same number of shells

Noble gases reactivity?

Unreactive

Why are noble gases unreactive?

Full outer shell

Old name for noble gases?

Inert gases

Boiling point trend G18?

Increases down the group

Density trend G18?

Increases down the group

Argon use?

Lamps

Helium use?

Balloons

Neon use?

Signs

Group 1 valence electrons?

1

Group 1 reactivity trend?

Increases down

Why more reactive down G1?

More shielding = easier to give away an electron

G1 Metal + water -> products?

Metal Hydroxide + H2

Na + water balanced equation ( including reactants )

2Na + 2H2O → 2NaOH + H2

Group 7 molecules are all?

Diatomic

Group 7 reactivity trend?

Decreases down

Why less reactive down G7?

More shielding = harder to attract electrons

Displacement reaction means?

More reactive replaces

Why Chlorine can't replace Fluorine in a compound?

Chlorine less reactive

Ionic bond formed by?

Electron transfer

Ionic lattice held by?

Electrostatic attraction

Dot-cross diagrams only show this on the atoms?

Valence electrons

Metal ion written how ( assume multiple different atoms in compound )?

Brackets, + charge

Non-metal ion written how ( assume multiple different atoms in compound )?

Brackets, - charge

Balance equations by?

Coefficients only

State symbol solid?

(s)

State symbol liquid?

(l)

State symbol gas?

(g)

State symbol aqueous?

(aq)

Why H2O never (aq)?

It is a solvent

Spectator ion?

Unchanged ion

Requirement for Net ionic equation?

No spectators