IB Chemistry - SL Topic 2

Dalton's theory that remains true

1. All matter (materials) consist of very small particles called atoms.
2. An element consists of atoms of one type only.
3. Compounds consist of atom of more than one element and are formed by combining atoms in whole-number ratios.
4. In a chemical reaction atoms are not created or destroyed.

Rutherford's gold foil experiment (1909)

1. The nucleus is very small compared to the rest of the atom.
2. There is lots of space in the atom.
3. All the positive charge is concentrated in the small nucleus.

Number of subatomic particles

3

Subatomic particles, location and charge

proton (+) - nucleus
neutron ( ) - nucleus

electron (-) - energy levels

protons + neutrons

nucleons

The number of protons in the nucleus of an atom.

atomic number

The number of protons plus the number of neutrons in an atom.

mass number

The subatomic particle with a relative mass of 1 and a relative charge of +1.

proton

The subatomic particle with a relative mass of 1 and no charge.

neutron

The subatomic particle with a relative mass of 0 and a negative charge.

electron

Atoms with the same atomic number but different atomic mass.

isotopes

This device is used to determine the relative atomic mass of an element by separating it's isotopes according to the m/z value.

mass spectrometer

Stage 1 of a mass spectrometer, where an atom or molecule is turned into a gas.

vaporization

Stage 2 of a mass spectrometer, where an atom or molecule is stripped of an electron.

ionization

Stage 3 of a mass spectrometer, where positive ions increase their speed when moving through an electric field.

acceleration

Stage 4 of a mass spectrometer, where positive ion are sent through a magnetic field.

deflection

Stage 5 of a mass spectrometer, where positive ions generate an electrical signal when they strike a sensor.

detection

The particle of energy that is released when electrons fall from a higher energy level to a lower energy level.

photon

The type of energy released when an electron falls from a higher energy level to the n=1 energy level.

UV

The type of energy released when an electron falls from a higher energy level to the n=2energy level.

visible light

The type of energy released when an electron falls from a higher energy level to the n=3 energy level.

IR

This term describes how energy levels get closer together as we move away from the nucleus of an atom.

convergence

This type of spectrum contains all frequencies/wavelengths/energies of waves.

electromagnetic spectrum

This type of spectrum contains all colors/wavelengths/frequencies/energies of visible light.

continuous spectrum

This type of spectrum contains specific/discrete colors/wavelengths/frequencies/energies of visible light on a black background.

line spectrum

An atom or ion with all it's electrons in the lowest energy levels possible.

ground state

An atom or ion with some electrons in higher energy levels.

excited state

This principle states that electrons fill the lowest energy levels first.

Aufbau principle

This principle states that any orbital can hold a maximum of two electrons and these electrons have opposite spin.

Pauli exclusion principle

The rule states that 1 electron must be placed in each orbital or equal energy before 2 electrons can be placed in a single orbital.

Hund's rule

The electrons found in the outermost energy level.

valence electrons

All the electrons not in the valence energy level.

core electrons

The electron arrangement of O (oxygen).

2, 6

The electron arrangement of Ca (calcium).

2, 8, 8, 2

The electron arrangement of Ne (neon).

2, 8

The electron arrangement of O1-.

2, 7

The electron arrangement of Ca1+.

2, 8, 1

The full electron configuration of P (phosphorus).

1s2 2s2 2p6 3s2 3p3

The full electron configuration of Fe (iron).

1s2 2s2 2p6 3s2 3p6 4s2 3d6

The full electron configuration of Cl1-.

1s2 2s2 2p6 3s2 3p6

The full electron configuration of Co3+

1s2 2s2 2p6 3s2 3p6 4s0 3d6

The electron configuration of Cr (chromium), using a noble gas core.

[Ar] 4s1 3d5

The electron configuration of Co(cobalt), using a noble gas core.

[Ar] 4s1 3d7

The electron configuration of Cu2+, using a noble gas core.

[Ar] 4s0 3d8

The number of unpaired electrons in C (carbon).

2

The number of unpaired electrons in N (nitrogen).

3

The number of unpaired electrons in Ca (calcium).

0

The number of unpaired electrons in F (fluorine).

1

In addition to Cr, Mo, and Cu, this element promotes one electron from the 4s to the 3d to promote stability.

Ag

An atom with the electron configuration of 1s2 2s2 2p6 3s2 3p6 4s0 3d10.

Cu

An atom with the electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10.

Zn

The weighted average of masses of all isotopes of an element relative to carbon-12.

relative atomic mass

An atom with more electrons than protons.

anion

An atom with more protons than electrons.

cation

An isotope that is radioactive.

radioisotope