Module 3-periodic table and energy Flashcards
Definition of first ionization energy?
Removal of one mol of electrons from one mol of gaseous atoms.
Definition of second ionisation energy?
Energy required to remove one electron from each ion in one mol of gaseous 1+ ions of an element to form one mol of gaseous 2+ ions.
What does ionisation energy measure?
How easily an atom loses electrons to form positive ions.
What factors affect attraction and ionisation energy?
- Atomic Radius ( the force of attraction falls off sharply with increasing distance)
- Nuclear charge (The more protons in the nucleus, the greater the attraction)
- Electron shielding (Electrons are negatively charged so inner shell electrons repel outer shell electrons. This repulsion is the shielding effect)
As the successive ionisation energy increases ( first, second, third) why does the energy needed to remove an electron increase?
As the number of electrons decreases, the number of protons will stay the same. Therefore, there will be more protons so the positive nuclei charge will become stronger, increasing attraction.
Does the atomic radius decrease or increase across a period?
Across a period, there are more protons, stronger attraction therefore the atomic radius will decrease.
Does the electro negativity increase or decrease across a period?
Across a period, there are more protons in nucleus, smaller atomic radius and stronger attraction so the electro negativity will increase.
Does first ionisation energy increase or decrease down a group?
Decrease because the shielding increases, atomic radius increases and increase in number of protons is outweighed by increase in distance and shielding.
What are the properties of giant metallic lattices?
-High melting and boiling points
- Good electrical conductors
-Malleability
-Ductility
What is the reactivity trend down group 2?
The reactivity increases down group 2
Why does the reactivity increases down group 2?
the atomic radius and shielding increases, decreasing the attraction between the nucleus and outer shell electrons. this means less energy is needed to remove the outer electrons, making the elements more reactive
what is the reactivity trend down group 7?
The reactivity decreases down group 7
Why does the bpt and mpt increase down group 7?
The molecules are larger and have more electrons. The London forces between the molecules are stronger and more energy is needed to overcome them.
why does the reactivity decrease down group 7?
The reactivity of the halogens decreases down the group because in order to become halides, halogens need to gain one electron, however with the increasing atomic radius which outweighs the nuclear attraction, it is harder for atoms with larger radiuses to pull in an electron.
why does the electronegativity decrease down group 7?
As you go down the group, there are more shells so more electron shielding and so the nuclear attraction to the bonding electrons is weaker.
what is disproportionation?
When the same element is both oxidised and reduced
why is chlorine added to water?
to kill any disease causing microorganisms
What are cons to adding chlorine to water?
-Chlorine is a toxic gas (respiratory irritant)
-Chlorine can chlorinate hydrocarbons and chlorinated hydrocarbons are suspected of causing cancer.
What is fluorine’s appearance and state at RTP?
Pale yellow gas
What is chlorines appearance and state at RTP?
Pale green gas
What is bromines appearance and state at RTP?
Red/brown liquid
What is iodines appearance and state at RTP?
Shiny grey/black solid
When chlorine reacts with bromide, what colour does the product bromine appear as?
Orange
When chlorine reacts with iodide, what is the product, iodines, colour?
Violet
