chapter 9 - group 2, the alkaline earth metals Flashcards
What happens to the atomic radius down a group
The atomic radius down a group increases as there are more electrons
What happens to the ionisation energy down the group
The ionisation energy decreases down the group
What happens to the electronegativity down the group
The electronegativity down group to decreases
What happens to the melting point down group 2
It generally decreases however there is an outlier and this is magnesium (magnesium is melting point is very low in comparison to the downwards trend
What is meant by the term atomic radius
Atomic radius is the distance from the nucleus to the outermost electron
What is meant by the term first ionisation energy
This is the energy required to remove one mole of electrons from one mole of gaseous atoms
What is meant by the term electronegativity
Electronegativity is the tendency of an atom to attract a pair of electrons in a covalent bond
What is the term melting point mean
It is the average temperature at which a substance goes from solid to liquid
Why does the melting point generally decrease down the group 2
The positive ions get bigger so the attraction from the nucleus to the sea of electrons decreases as you go down group 2. Magnesium is an outlier and there has a much lower melting point than the general trend as it has a HCP
Our group 1 metals more or less reactive than group 2 metals
Group 1 metals are more reactive than group 2 metals as the outer electrons are harder to remove in group two and an outer electron is more easily lost in group 1 as it has one less proton.Therefore making group 1 metals more reactive than group 2
Reactions of group to metals
/ elements with water
Magnesium ribbon and water
Observation-no change/slight effervescence
Observation with a lit splint-no change
Observation with three drops of universal indicator- neutral/ yellow green
Reactions of group 2 metals/elements with water
Magnesium powder with water
Observation- slight effervescence
Observation with a lit splint-Squeaky pop/no change
Observation with three drops of universal indicator-green/blue PH8
Reactions of group 2 metals/elements with water
Calcium granules and water
Observation-effervescence, vigourous reaction, white precipitate
Observation with a lit splint-squeaky pop
Observation with three drops of universal indicator-blue PH 10
Reactions of group 2 metals/elements with water
Stronium(prediction)
Observation-catches flame
Observation with lit splint-squeaky pop
Observation with three drops of universal indicator-PH11/12
Reactions of group 2 metals/elements with water
beryllium (prediction)
Observation-effervescence
Observation with a lit splint-squeaky pop
Observation with three drops of indicator-pH 7/8
