topic three/thirteen Flashcards
what is nuclear charge the same as
atomic number
what does the period number tell us
gives the number of occupied main energy levels in the atom
what does the group number tell us
number of valence electrons
metals are mainly located wehre on the periodic table
s block, d block, f block
characteristic properties of alkali metals
The most reactive group of metals – react strongly with cold water.
characteristic properties of alkaline earth metals
Reactive metals – but less reactive than group 1.
characteristic properties of the halogens
The most reactive group of non-metals.
characteristic properties of the noble gases
A group of very unreactive monatomic gases.
characteristic properties of the transition metals
Relatively stable metals with only moderate reactivity – useful for construction.
what are lanthanides and actinides
metallic elements that make up the f block
s block
groups 1 and 2
d block
groups 3 to 12
p block
13 to 18
f block
bottom of the periodic table
what does the block of an element tell us
which sub level is in the process of being filled
which block are hydrogen and helium
s block although often placed above group 1
what is a transition element
defined as an element that has an incomplete d sub-level in its atom or one or more of its ions.
properties of transition elements
They have variable oxidation states.
They form coloured compounds.
The elements or their compounds show catalytic activity.
They form complex ions in solution.
The metals and their complexes show magnetic properties.
why is scandium the only element that cant have a +2 oxidation state
ha sonly one unparied d electron
what is the reason for these variable oxidation states is
the closeness in energy of the 3d and 4s sub-levels.
what is an ionic bond
an electrostatic attraction between oppositely-charged ions. Ionic bonds are formed by elements with an electronegativity difference of approximately 1.8 units and greater.
