The Periodic Table Flashcards
in what order does the periodic table show the elements in?
- in order of increasing atomic number.
- also, the elements with similar properties form columns. (these vertical columns are called groups)
what does the group which an element belongs corresponds to?
it corresponds to the number of electrons in its outer shell (group 1 has 1 outer shell electron, group 2 elements has 2 outer shell electrons, etc.)
what is the name of group 1 elements?
alkali metals
what is the name of group 7 elements?
halogens
what is the name of group 0 elements?
noble gases
what are the rows called in the periodic table?
they are called periods
what happens as the periodic table goes along
the properties of elements change.
what are the 3 electron shell rules?
- electrons always occupy shells (sometimes called energy levels)
- the lowest energy levels are always filled up first (the lowest energy levels are the ones closest to the nucleus)
- only a certain number is allowed in each shell: 1st -> 2, 2nd -> 8, 3rd -> 8
how are shells shown in a diagram?
shells are shown as circles around the nucleus. The Xs on the circle are the electrons.
how do you find out the electronic configuration?
e. g Nitrogen
- The atomic number for nitrogen is 7. That means nitrogen has 7 protons and 7 electrons.
- Follow the electron shell rule (1st -> 2, 2nd -> 8, 3rd -> 8). The first cell can only take 2 electrons, and the second shell can take max. 8 electrons. So the electronic configuration must be 2.5
what are the metals in the periodic table?
they are in the left- hand side.
what are the non-metals in the periodic table?
in the right- hand side.
why do metals conduct electricity?
because they can allow charge to pass through them easily.
what does it mean when you say ‘Metal oxides are basic’?
this means they will neutralise acids. Metal oxides that dissolve will form solutions with a pH of more than 7.
what does it mean when you say ‘Non-metal are acidic’?
it means that they will neutralise bases. They dissolve in water to form solutions with a pH of less than 7.
are non-metals good at conducting electricity?
no, non- metals are poor conductors of electricity.
what are 3 facts about group 0 elements?
- they are called noble gases which include helium, neon, and argon (plus a few other).
- they are inert - don’t react with much at all.
- the reason that they don’t react with much at all is because it takes a lot of energy to add or remove electrons from a noble gas atom.
what are ions?
ions are charged particles they can be single atoms (e.g Na+) or group atoms (e.g NO3-)
when/how are negative ions (anions) formed?
when atoms gain electrons - they have more electrons than protons
when/how are positive ions (cations) formed?
when atoms lose electrons - they have more protons than electrons.
what does it mean when an ion loses or gains electrons?
the lose or gain of electron is equal to the charge of the ion. E.g if 2 electrons are lost the charge is 2+, but if 3 electrons are gained the charge is 3-
what happens when group 1, 2, 3 (metals) lose electrons?
they form positive ions
what happens when group 5, 6, 7 (non-metals) gain electrons?
they form negative ions
what do elements in the same group all have in common?
they all have the same number of electrons in the outer shell. this means that they form ions with the same charge
