Topic 1 Flashcards
Define relative atomic mass
The weighted mean mass of an atom of an element compared to 1/12th of the mass of an atom of carbon-12
Define relative isotopic mass
The mass of an atom of an isotope compared with 1/12th of the mass of an atom of carbon-12
In mass spectrometry the M peak is the same as what
RAM value
Define the first ionisation energy
The energy needed to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions
What are the three factors that affect ionisation energy
Nuclear charge, electron shells, shielding
How does the nuclear charge affect the ionisation energy
The more protons in the nucleus the more positively charged the nucleus is and the stronger the attraction for the electrons
How does the number of electron shells affect the ionisation energy
An electron in an electron shell closer to the nucleus will be much more strongly attracted than one in a shell further away
How does shielding affect ionisation energy
As the number of electrons between the outer electrons and the nucleus increases the outer electrons the less attraction towards the new discharge
What is the trend in the first ionisation energy as you go down the group?
As you go down the group the ionisation energy decreases because it becomes easier to remove outer electrons due to more shielding so less attraction between outer electrons and nucleus
What is the trend in atomic radius across a period
As you go across the period the positive charge on the nucleus increases so electrons are pulled in closer so atomic radius decreases
What is the trend in ionisation energy across a period
As you move across the period the general trend increases because it becomes harder to remove outer electrons due to a stronger nuclear attraction
