Chem GCSE periodic table Flashcards
Why did Newlands table not work?
*mixed up metals and non metals
*left no gaps for undiscovered elements
*pattern only worked for 20 elements
How did Newlands arrange the periodic table?
In order of increasing atomic weight
What did Newlands name his rule
The octave rule
How are atoms arranged
In order of their atomic number
What are atoms arranged in
In groups (columns) due to similar properties
How did Mendeleev arrange his periodic table
Elements are in groups in order of their atomic weight
What are isotopes
Are atoms with the same number of protons but different number of neutrons
How is the modern periodic table arranged
*in order of increasing atomic number
*elements in the same group have the same number of electrons in their highest energy level
Properties of metals
Good conductors of heat & electricity, ductile, high melting points
Properties of non metals
Poor conductors of heat & electricity, often liquids and gasses
Chemical properties of metal
Have metallic bonding, form ionic compounds by loosing electrons
Chemical properties of non metals
Are covalent molecules and form ionic compounds by gaining electrons, they form covalent compounds by (with non metals) sharing a pair of electrons
Alkali metals
Have one electron in their highest energy level, have a low density
What is the melting and boiling point like in group 1
Melting and boiling point decreases going down
Reactivity in group 1
Reactivity increases going down group 1
The halogens
Have 7 electrons in their highest energy level, coloured vapour and react with metals to form salts
Melting and boiling point in group 7
Melting and boiling point increases going down
Reactivity in group 7
Reactivity decreases going down
Nobel gasses
Very unreactive as they have a full highest energy level, 8 electrons in highest energy level
Boiling point in group 8
Boiling point increases going down the group
Properties of transition metals
Good conductors of electricity & heat, can easily be hammered into shape
Melting point of transition elements
Higher melting point compared to the alkali metals
Compared to the alkali metals, transition elements:
Have higher densities, harder and stronger, less reactive
Transition metals: coloured compounds
Cu2+ = blue
Fe2+ = pale green
Ni2+ = green
Reactivity of transition metals:
They react slowly with oxygen to form ionic salts, don’t react with cold water
