1.1 Atomic Structure Flashcards Preview

Chemistry AS 2015-16 > 1.1 Atomic Structure > Flashcards

Flashcards in 1.1 Atomic Structure Deck (30)
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1

What is atomic mass?

Number of protons in an atom (and therefore also electrons)

2

What is mass number?

Total number of protons and neutrons

3

What are isotopes?

Isotopes are atoms with the same number of protons but different numbers of neutrons, and therefore a different mass number

4

Name the stages of the mass spectrometer

Ionisation, acceleration, ion drift (in the flight tube), detection, data analysis

5

What must you account for when calculating the relative atomic mass from mass spectra?

The relative abundances of isotopes

6

How many electrons does each atomic orbitals hold?

s holds 2, p holds 6, d holds 10

7

Name the sub atomic particles which make up an atom

Proton, electron,neutron

8

What is ionisation energy?

The energy needed to remove one mole of electrons from one mole of atoms in a gaseous state

9

What is the general trend in ionisation energy across a period?

General increase alone a period due to increasing nuclear charge

10

What are the relative masses and charges of the sub atomic particles?

Neutron: 1, 0 Proton, 1, +1 Electron, 1/1840, -1

11

What holds electrons and protons together in an atom?

Electrostatic forces of attraction

12

How do you calculate the mass number?

number of protons + number of neutrons (the total number of nucleons)

13

Define the term relative atomic mass

The average mass of an atom compared to the mass of 1/12 of a carbon 12 atom

14

Explain why a time of flight mass spectrometer is kept under a vacuum

To prevent the ions that are produced colliding with molecules from the air

15

What causes the ions to accelerate through a mass spectrometer?

They are attracted by a negatively charged plate

16

Give the electronic configuration, showing all the sub levels, of a calcium atom

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

17

What is the relative mass of an electron?

1/1840

18

What is meant by the term first ionisation energy?

The enthalpy change needed to move an electron from the outer most shell of an atom

19

Why does the first ionisation energy generally decrease as you go down a group?

Down a group there is more electron shielding because there are increasing numbers of electron shells. Therefore the outer electrons are further from the nucleus and thus easier to remove.

20

Why does the first ionisation energy generally increase as you go across a period?

As you move across a period, the atomic radius decreases. This means the outer electrons are closer to the nucleus and more strongly attracted to the center. Therefore, it becomes more difficult to remove the outermost electron.

21

What holds electrons and protons together in an atom?

Electrostatic forces of attraction

22

How do you calculate the mass number?

number of protons + number of neutrons (the total number of nucleons)

23

Define the term relative atomic mass

The average mass of an atom compared to the mass of 1/12 of a carbon 12 atom

24

Explain why a time of flight mass spectrometer is kept under a vacuum

To prevent the ions that are produced colliding with molecules from the air

25

What causes the ions to accelerate through a mass spectrometer?

They are attracted by a negatively charged plate

26

Give the electronic configuration, showing all the sub levels, of a calcium atom

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

27

What is the relative mass of an electron?

1/1840

28

What is meant by the term first ionisation energy?

The enthalpy change needed to move an electron from the outer most shell of an atom

29

Why does the first ionisation energy generally decrease as you go down a group?

Down a group there is more electron shielding because there are increasing numbers of electron shells. Therefore the outer electrons are further from the nucleus and thus easier to remove.

30

Why does the first ionisation energy generally increase as you go across a period?

As you move across a period, the atomic radius decreases. This means the outer electrons are closer to the nucleus and more strongly attracted to the center. Therefore, it becomes more difficult to remove the outermost electron.