The periodic table Flashcards
the number of protons in an atom is the same as the…
number of electrons and is called the atomic number
what is the name for the configuration and distance that the electrons are away from the nucleus
electronic configuration
and shells
are elements on the periodic table listed in order of increasing or decreasing atomic numbers
increasing
what are the horizontal rows called on the periodic table
periods
what are the vertical rows called on the periodic table
groups
what is the group number the same as
the number of electrons in the outermost shell
elements in the same group have similar what
chemical properties, because they have the same number of electrons on their outer shell
what is group 1 called
alkali metals
why is group 1 called alkali metals
because they all react with water to form alkaline solutions
what is group 7 called
halogens
why is group 7 called halogens
it means ‘salt maker’, halogens form salts when they react with metals
why is group 7 called halogens
it means ‘salt maker’, halogens form salts when they react with metals
what is group 8/0 called
noble gases
why is group 8/0 called noble gases
because they are unreactive (full outer shell)
how does the periodic table change from left to right
gradually from metal to non metal
what is another word for a semi-metal
a metalloid (it has some metal properties but isn’t actually a metal)
6 metals of group 1
lithium sodium potassium rubidium caesium francium (radioactive and little know about its properties)
lithium sodium and potassium physical properties
- good conductors of electricity and of heat
- soft and can easily be cut with a knife
- low melting and boiling points compared with more typical metals
- low densities (all float on water)
- stored in oil at schools
lithium sodium and potassium chemical properties
- shiny surfaces when freshly cut, but quickly tarnishes as it reacts with oxygen in the air
- all burn in air or oxygen to form white and solid oxides:
2M + O2 –> M2O
M= one of the three metals - they react vigorously with water to give an alkaline solution of the metal hydroxide as well as hydrogen gas :
2M + 2H2O –> 2MOH + H2
observations when lithium is added to water
- moves around the surface of the water
- hissing sound
- bubble of gas
- gets smaller and smaller –> eventually disappears
observations when lithium is added to water
- moves around the surface of the water
- hissing sound
- bubble of gas
- gets smaller and smaller –> eventually disappears
observations when sodium is added to water
- moves around the surface of the water
- hissing sound
- bubble of gas
- gets smaller and smaller –> eventually disappears
- melts into a shiny ball
observations when potassium is added to water
- moves around the surface of the water
- hissing sound
- bubble of gas
- gets smaller and smaller –> eventually disappears
- melts into a shiny ball
- burns with a lilac coloured flame
the further you go down group 1 what should we observe
more reactive metals
the further down group 1 less energy is needed to overcome the electrostatic forces of attraction with the ext a outside electron therefore
- francium is the most reactive out of group 1
- the size of the atom increases and therefore the outer electron gets further away from the nucleus
- the outer electron is therefore less strongly attracted to the nucleus
the further down group 1 less energy is needed to overcome the electrostatic forces of attraction with the ext a outside electron therefore
- francium is the most reactive out of group 1
- the size of the atom increases and therefore the outer electron gets further away from the nucleus
- the outer electron is therefore less strongly attracted to the nucleus
3 most common metals from the halogens
chlorine, bromine and iodine (all non metals and poisonous)
state at room temp and colour: chlorine
gas
pale green
state at room temp and colour: bromine
liquid
red-brown (readily evaporates to form a brown gas)
state at room temp and colour: iodine
solid
black (but sublimes when heated to form a purple gas)
how do the three main elements from the halogens react with iron similarly:
hot iron wool glows brightly when chlorine passes over it. brown smoke forms and a brown solid is left behind.
how do the three main elements from the halogens react with iron similarly:
Chlorine: hot iron wool glows brightly when chlorine passes over it. brown smoke forms and a brown solid is left behind.
Bromine: hot iron wool glows less brightly when bromine vapour passes over it. brown smoke forms and a brown solid is formed.
Iodine: hot iron wool glows even less brightly when iodine vapour passes over it. brown smoke forms and a brown solid is formed.