Aqa Chemistry As (Atomic Structure)

Front 1

Name the three types of particle in an atom. State the relative mass and charge of each particle.

Back 1

>Proton - mass 1, charge +1
>Neutron - mass 1, charge 0
>Electron - mass 1/1840, -1

Front 2

How are the particles in an atom arranged?

Back 2

Protons and neutrons in central nucleus held by strong nuclear force. Electrons orbit nucleus in shells (electrostatic force).

Front 3

How many electrons do the first shells hold?

Back 3

2n squared / n = number of shell
1st = 2
2nd = 8
3rd = 18

Front 4

Write the shorthand for 9 electrons.

Back 4

2,7,

Front 5

Draw the electron arrangement diagram of an atom with 16 electrons.

Back 5

Front 6

Define the term mass number, A.

Back 6

The sum of the protons and neutrons in the nucleus of an atom.

Front 7

Define the term atomic number, Z.

Back 7

The number of protons in the nucleus of an atom.

Front 8

Define the term Isotope.

Back 8

Atoms with the same number of protons but different numbers of neutrons.

Front 9

Why do isotopes of the same element have identical chemical properties?

Back 9

They have the same number and arrangement of electrons.

Front 10

What does a mass spectrometer measure?

Back 10

Relative atomic masses
Relative molecular masses

Front 11

Back 11

63.6

Front 12

Describe how a mass spectrometer works (the 6 stages).

Back 12

The instrument is kept under a high vacuum so that the ions do not collide with air molecules.
>Vaporisation - sample injected into instrument if gaseous or volatile liquid, if solid is vaporised by heating
>Ionisation - sample is passed through stream of high energy electrons from a beam of electrons from electron gun knocks out electrons to form positive ions. Nearly all atoms or molecules lose just one electron and form ions with a 1+ charge but a small number (typically around 5%) lose two electrons to form ions with a 2 + charge
>Acceleration - positive ions are attracted towards negatively charged plates and are accelerated to high speed.
>Deflection - Magnetic field deflects beam into an arc circle. Heavier ions are deflected less and 2+ ions are deflected twice as much as 1+ ions with same mass. Stronger field, greater deflection.
>Detection - magnetic field is gradually increased so that ions of increasing mass enter detector one after another. Ions strike detector, and create a current which is proportional to the abundance of each ion. From strength of magnetic field at which a particular ion hits detector, a computer works out value of charge ratio of original ion.

Front 13

Write down the sub-shells in order of increasing energy up to 4f?

Back 13

Front 14

What does arrow-in-box notation look like?

Back 14

Front 15

a) Which are the two anomalies involving electronic structure?
b) Why?

Back 15

a) Chromium (Cr) and Copper (Cu)
b) They donate one of their 4s electrons to the 3d sub-shell (they only have one 4s electron)

Front 16

Define the term first ionisation energy (IE).

Back 16

The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous positive ions.

Front 17

Sketch a graph of the successive ionisation energies of sodium?

Back 17

Front 18

Sometimes you may need to measure with ruler.

Back 18

Front 19

Label axis for spectrometer graph.

Back 19

Side - Abundance (%)
Bottom - Mass:Charge ratio (m/z)