ATOMIC STRUCTURE Flashcards

1
Q

Describe the process of Electron-Impact Ionisation

A

Sample is vapourised
High-energy electrons are fired at sample
from an electron gun
One electron is knocked off each particle

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2
Q

Give two reasons why it is necessary to ionise the isotopes of chromium before they can be analysed in a TOF mass spectrometer.

A

accelerated/Allow (ions) accelerated to a negative plate

ions create a current in the detector by picking up an electron
Allow (ions) can be detected

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3
Q

Explain why the ionisation energy of every element is endothermic

A

Heat or energy needed to overcome the attraction between the (negative) electron and the (positive) nucleus or protons

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4
Q

Explain why the second ionisation energy of boron is higher than the first ionisation energy of boron 1

A

Second electron is removed from a positive ion

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5
Q

what did Rutherford discover and through what experiment evidence is there

A

discovered nucleus and that’s its very small and most atom is empty space
Rutherford fired He2+ ions at a sheet of gold foil. most went through bcz atom is mostly empty space and small number of them deflected back because of the small positive nucleus

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6
Q

what did bohr discover

A

electrons in enegy shells

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7
Q

why is the second IE of boron is higher than the first IE of boron 2

A

forms a positive ion
more protons compared to electrons due to electron loss
attraction over remaining electrons is stronger therefore requires more energy

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8
Q

why is the second IE of rubidium larger than the second IE of strontium 2

A

WRITE ELECTON CONFIGURATION OUT
Rb - 2nd e- removed from a shell closer to the nucleus (lower energy level)
stronger nuclear attraction for Rb e-

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9
Q

Explain why the second ionisation energy of calcium is lower than the second ionisation energy of potassium 2.

A

DO ELECTRON CONFIGURATION so know which electron is being removed
In Ca(+) (outer) electron(s) is further from nucleus

More shielding (in Ca+

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10
Q

Deduce which of Na+ and Mg2+ is the smaller ion.

Explain your answer.

A

Mg(2+) or Magnesium

Because Mg2+ has more protons

AND

With the same shielding/ screening/electron arrangement/ number of electrons (or isoelectronic)

Allow larger/stronger nuclear charge

Ignore atomic radiu

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11
Q

State the meaning of the term first ionisation energy of an atom.

A

energy change/required when a mole of electrons is removed/ knocked out / displaced/ to form a positive ion

from a mole of gaseous atoms

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12
Q

Explain why the value of the first ionisation energy of neon is higher than that of sodium. 2

A

Electron removed from a shell of lower energy or smaller atom or e– nearer to nucleus

Less shielding

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13
Q

In terms of the electron sub-levels involved, explain the position of aluminium and the position of sulphur 4

A

AL outer electron in (3)p sub-shell

Sub-shell further away from nucleus OR of higher energy level so easier to remove e-

Explanation for sulphur: Pair of electrons in (3)p orbital

Repulsion between electrons

(4

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14
Q

A student studying GCSE science is puzzled by data which indicate that a sodium atom is larger than a chlorine atom and that a sodium ion is smaller than a chloride ion. How should an A–level Chemistry student explain this apparently conflicting information. 6

A

A chlorine atom has more protons in its nucleus than a sodium atom has

Both have three shells of electrons

Electrons more strongly attracted by chlorine nucleus so size smaller than Na

An electron shell is lost when a sodium ion is formed from a sodium atom

Inner electrons more strongly attracted so ion smaller than atom

An electron is added to the outer shell when a chloride ion is formed

Greater repulsion between shells so size of chloride ion greater than Cl atom

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15
Q

Explain why the value of the first ionisation energy of sulfur is less than the value of the first ionisation energy of phosphorus. 2

A

Paired electrons in (3)p orbital

repel

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