The periodic table Flashcards
where are metals and non-metals in the periodic table?
from left to right across the periodic table there is a gradual change from metal to non-metal
how are elements classified as metal and non-metal?
- if an element is electrically conductive and its oxide is basic, then it’s a metal
- If an element is non electrically conductive and its oxide is acidic, then its a non-metal
what are metals?
metals are all conductors and they form metal-oxides, which are alkaline
what are non-metals?
non-metals don’t conduct and they form non-metal oxides, which are acidic
what happens when magnesium reacts with oxygen?
magnesium burns with a bright, white flame to form a white ash of magnesium oxide
what happens when carbon reacts with oxygen?
carbon burns with a yellow/orange flame to form a colourless gas: co2
what happens when sulfur reacts with oxygen?
sulfur burns with a blue flame to form a colourless gas
why do elements in the same group have similar chemical properties?
because they have the same number of electrons in their outer shell
what is the role of the electrons in the outermost shell?
the electrons in the outermost occupied cell determine the chemical properties of the atom; it is called the valence shell
what are the noble gases?
group 8/0 are called the noble gases. These elements do not form compounds with other elements
what does inert mean?
chemically unreactive
why are noble gases not reactive?
they do not react because they have a full outer shell in each atom, which makes them stable. Having a full outer shell means they do not need to gain, or lose electrons.
what happens when group 1 elements react with water?
group 1 elements react vigorously with water to give an alkaline solution of the metal hydroxide as well as hydrogen gas.
what changes as you go down the elements in a group?
the elements are more reactive
what happens when lithium reacts with water?
- moves around the surface of the water
- hissing sound
- bubbles of gas
- gets smaller and smaller; eventually disappears
what happens when sodium reacts with water?
- moves around the surface of the water
- hissing sound
- bubbles of gas
- melts into a shiny ball
- gets smaller and smaller; eventually disappears
what happens when potassium reacts with water?
- moves around the surface of the water
- hissing sound
- bubbles of gas
- melts into a shiny ball
- burns with a lilac-coloured flame
- gets smaller and smaller; eventually disappears
what trends can we see from the reactions of the elements in group 1?
the further down the group we get, the more reactive the elements are
why does reactivity increase down group 1?
as you go down group 1, the number of electron shells increases. Lithium has 2 sodium has 3 etc. Therefore, the outermost electron gets further away from the nucleus. The attraction from the positive nucleus and the negative electron is less. This makes it easier to remove the electron and makes the atom more reactive
what colour and physical state is chlorine at room temperature?
chlorine is a gas at room temperature and is pale green
what colour and physical state is bromine at room temperature?
bromine is a liquid at room temperature and is red/brown
what colour and physical state is iodine at room temperature?
iodine is a solid at room temperature and is black/dark grey
what is group 7?
the halogens