IB Chemistry HL: Topic 2

Mass, charge, and location of a proton

1 amu, +1, nucleus

Mass, charge, and location of a neutron

1 amu, 0, nucleus

Mass, charge, and location of an electron

1/1840 amu, -1, energy cells (outside of nucleus)

Isotope

A different number of neutrons than the original atom -- same charge, different mass

Relative Atomic Mass

The averaged atomic masses of all isotopes (this is how the atomic mass of the elements is determined)

Mass Spectrometer: Purpose

Measuring the masses of atoms

The Steps of Mass Spectroscopy 1-6

1. injection of sample

2. vaporisation of sample

3. ionisation of sample

4. acceleration of ions

5. deflection of ions

6. detection of masses of ions

Continuous Emission

"The emission spectrum is a combination of the atomic spectra of the various kinds of atoms making up the substance and can be analyzed to determine the substance's chemical or atomic composition." -- thefreedictionary.com

Continuous Absorption

The range of electromagnetic frequencies absorbed by a specimen.

Line Emission

The spectrum of lines or bands emitted by a substance

Line Absorption

The spectrum of lines or bands absorbed by a substance

The difference between line and continuous

Continuous: broad bands

Line: discrete lines or emissions

Equation for energy and electromagnetic wave length

E = hv

E = hv What does it mean?

E = energy

h = planck's constant

v = wave length

What defines ionization energy

1. Charge of the nucleus

2. The distance of the outer electron from the nucleus

3. The number of electrons between the outer electron and the nucleus

First Ionization Energy

The amount of energy needed to remove one mole of electrons from one mole of a gaseous substance

Successive Ionization Energy

The same, but from already charged atoms

Does ionization energy increase or decrease as successive electrons are removed?

Increase

Order of the four energy shells

s, p, d, f from least to most energy

The three rules for filling electron shells

1. Always enter orbital of lowest energy

2. Electrons fill up an orbital singly first, then fill doubly

3. There can be no more than two electrons per orbital