| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Why does General increase in IE, across a period | -Across a period, nuclear charge increases
- Electrons removed comes from the same shell.
- Force of attraction between positive nucleus and outer negative electrons increases because |
| Why does General increase in IE, across a period | -Across a period, nuclear charge increases
- Electrons removed comes from the same shell.
- Force of attraction between positive nucleus and outer negative electrons increases because |
| Why does General increase in IE, across a period | -Across a period, nuclear charge increases
- Electrons removed comes from the same shell.
- Force of attraction between positive nucleus and outer negative electrons increases because |
| Why does General increase in IE, across a period | -Across a period, nuclear charge increases
- Electrons removed comes from the same shell.
- Force of attraction between positive nucleus and outer negative electrons increases because |
| Why does General increase in IE, across a period | -Across a period, nuclear charge increases
- Electrons removed comes from the same shell.
- Force of attraction between positive nucleus and outer negative electrons increases because |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
| How are principal quantum shells numbered? | Principle quantum shells (symbol n) are numbered according to how far they are from the nucleus. |
| What is the arrangement of electrons in an atom called? | Electron configuration |
| What is the max number of electrons that each principle quantum shells can hold? Shells 1- 4 | Shell 1 - Up to 2 electrons
Shell 2 - Up to 8 electrons
Shell 3 - Up to 18 electrons
Shell 4 - Up to 32 electrons |
| What is the first ionisation energy? | The first ionisation energy of an element is the energy needed to remove one electron from each atom in one mole of atoms of the element in gaseous state to form one mole of gaseous 1+ ions. |
| What is successive ionisation energies? | We can continue to remove electrons from an atom until only the nucleus is left. Sequence of ionisation energies is known as successive ionisation energies. |
| Explain how and why for each element, successive ionisation energies increases? | For each element, successive ionisation energies increases because net positive charge on ion gets greater as each element is removed.
As each electron is removed there is a greater attractive force between positively charged protons in the nucleus and remaining negative charged electrons
More energy is needed to overcome these attractive forces. |
| Why Size of the nuclear charge influence ionisation energy? (4) | - As atomic number increases, positive nuclear charge in
nucleus increases
- Bigger the positive charge the greater the attractive
force between nucleus and electrons
- More energy is needed to overcome attractive forces if
an electron is to be removed
- Ionisation energy increases as proton number increases |
| Why distance of outer electrons from the nucleus, Influence ionisation energy (3) | - Forces of attraction between positive and negative charges decreases rapidly as distance between them increases
- Electrons in shells further away from nucleus are less attracted to nucleus than those closer to the nucleus
- Further outer electrons shell is from nucleus, the lower the ionisation energy. |
| Why does shielding effect of inner electrons , influence ionisation energy (5) | - Electrons are negatively charged, so they repel each other
- Electrons in full inner shells repel electrons in outershells
- Full inner shells of electrons prevent outer electrons prevent outer electrons from feeling full nuclear charge, this is called shielding
- Greater the shielding of outer electrons by the inner electrons shells, the lower the attractive force between the nucleus and the outer electrons.
- Ionisation energy is lower as the number of full electron shells between outer electrons and nucleus increases |
| How does Spin-pair repulsion, influence ionisation energy? | - Electron in same atomic orbital in a sub-shell repel each other more than electrons in different atomic orbitals
- Increased repulsion makes it easier to remove on electrons
- First ionisation energy is decreased. |
| How can we use successive ionisation energies ? | - Predict / confirm the simple electron configuration of elements
- Confirm number of electrons in outer shell of an element and hence the group to which the element belongs
- Deduce which group an element belongs to in Periodic table |
| When high-speed electrons hit gas particles at low pressure, coloured lines are seen through instrument called? | Spectroscope |
| What are atomic orbitals? | An atomic orbital is a region of space around the nucleus of an atom that can be occupied by 1 or 2 electrons |
| Atomic Orbitals can only hold max 2 electrons, number of orbitals in each sub-shell must be : | s - 1 orbital
p - 3 orbitals
d- 5 orbitals |
| The first principle quantum level can hold max number (1) of electrons in what sub-shell (2) | First principle quantum shell can hold max 2 electrons in s sub-shell |
| The third principle quantum level can have max of (1) electron, in all the sub-shells. How are they distributed | 2 electrons in s sub-shell
6 Electrons in p sub-shell
10 Electrons in d sub-shell |
| The second principle quantum level can hold max number of (1) electrons, and how are they distributed | 2 electrons in s sub-shell
6 electrons in p sub-shell |
| What is the electronic configuration of potassium? | 1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 |
| What is Spin-pair repulsion | Electrons in same region of space repel each other because they have same charge |
| What is free radical? | A free radical is a species with one or more unpaired electrons |
| Why are Stable metal ions smaller than atoms? | Stable metal ions are smaller than metal atoms because the atoms have lost their outer shell electrons, so the attractive forces between the nucleus and outer electrons are larger. |
| Why do Stable non-metal ions larger than metal atoms? | Stable non-metal ions are larger than metal atoms because the atoms have gained electrons to complete their outer shells, so attractive forces between nucleus and outer electrons is smaller. |
| Why does the atomic radius increases down any group? | because each successive elements have one more shell of electrons which is further from the nucleus. |
| Why does the atomic radius decrease across any period | - Because of the proton number
- The nuclear charge increases by 1, extra electron
added goes into same (outer) energy level.
- Shielding does not change |
| Does ionic radius (increase / decrease) down any group (for ions with same charge) | increases |
| Does ionic radius ( increase / decrease ) across a period from Group 1 - Group 14 | Decreases |
| Why does General increase in IE, across a period influence ionisation energies? | -Across a period, nuclear charge increases
- Electrons removed comes from the same shell.
- Force of attraction between positive nucleus and outer negative electrons increases. |
| Why does Rapid decrease in ionisation energy between last element in one period and the first element in next period influence ionisation energies? | - Forces of attraction between positive nucleus and outer negative electrons because distance between the nucleus and the outer electrons increases, and shielding of inner shells increases. |
| Why does slight decrease in IE1 between beryllium and boron influence ionisation energies? | - Boron has 1 more proton than beryllium, there is slight decrease in IE1 on removal of outer electrons
- beryllium has electron structure 1s^2 2s^2 and boron has electron structure 1s^2 2s^2 2p^1
- Less attractive between 5th electron in boron and nucleus because, distance between nucleus and outer electron increases slightly, shielding by inner shells increases slightly |
| Why does Slightly decrease in EI2 between nitrogen and oxygen influence ionisation energies? | - Oxygen has 1 more proton than nitrogen, electron removed is in 2p sub shell
- Electrons removed from nitrogen is from orbital that contains an unpaired electrons
- Electrons removed from oxygen is from orbital that contains a pair of electrons
- Extra repulsion between pair of electrons in this orbitals results in less energy being needed to remove an electron.
- IE1 for oxygen is lower because of spin pair repulsion |
| Nuclear charge is increasing down the group there is less attraction between outer electrons and the nucleus, because : | - Distance between nucleus and outer electrons increases
- Shielding by complete inner shells increases |
