Periodicity- Trends in group 2 Flashcards
Who is john dobereiner?
- a german chemist
- in 1817-1829 came up with the law of triads
- triads is a group of 3 elements that have similar chemical and physical properties
- when arranged the average atomic mass is equal to the mass of the middle element
Who is dimitri mendeleev?
- a russian chemist
- arranged elements based on their relative atomic mass and left space for undiscovered elements
- made the first version of the periodic table
What are the elements of group 2 called?
alkaline earth elements
What are the first 5 elements of group 2?
Berylium
Magnesium
Calcium
Strontium
Barium
What is berylium and uses
a soft silver white metal
used to make gears and cogs in the aviation industry
used in alloys
What is magnesium and uses
part of a chrlorophyll molecule
used to make laptop carseats and cameras
used in fireworks
What are the uses of calcium?
used in milk for strong bones and teeth
Ca0- used to make cement
Ca(OH)2- used to neutralize cane juice
Uses of scrontium
gives the red colour in fireworks
glow in the dark plastics and paint
uses of barium
posenous to man
used in vaccum as drying agent
What is the trent of the atomic radius in group 2?
The atomic radius increases down the group because the number of shell increases and the valence electrons attraction to the nucleus decreases
What is the trend of the ease of ionization in group 2?
increases down the group because its easier for the atoms to lose electron due to the attraction of the valence electrons and nucleus decreasing
Reactivity in group 2
increases down the group
The atoms are easier to ionize which makes them more and more reactive
reactions are more vigorous down the group
Metals react with 02 to form?
oxides
metals react with water to form?
metal hydroxides and hydrogen
Metals react with acids to form?
salt and hydrogen gas
