Section 2-The Periodic Table and Bonding P1 Flashcards
What is the periodic table?
The Periodic Table is a table of all known elements.
-Dmitri Mendeleev ordered the elements by atomic mass to make a table of elements
How is the periodic table arranged?
-its laid out in columns (groups) and rows (periods)
What are the features of groups?
- have similar properties
- group number corresponds to the number of electrons in its outer most shell
What are the features of periods?
-determines the number of shells an element will have
What are the special names for?
Group 1 elements:
Group 7 elements:
Group 0/8 elements:
Group 1 = alkali metals
Group 7 = halogens
group 0/8 = noble gases
How was the periodic table made?
The periodic table was made by looking at the properties of the elements and arranging them into groups, the same groups that they have today.
What does the properties of elements depend on?
The properties depend on the number of electrons
- atomic number is therefore significant because it equals the number of electrons
- the number of electrons in the outer most shell is the most important for chemical properties
What are the electron shell rules:
- electrons always occupy shells, always building from inside out
- 1st shell has 2 electrons, 2nd and 3rd shell have 8 electrons
- atoms always try to have full outer shells, but in most atoms the outer shell isn’t full so they want to react to get a full outer shell
How do you work out electronic configurations?
- find out the atomic number
- start from the inner most shell and fill the with 2 from the atomic number and then carry on for as many electrons you have, adding another shell every 8
How do you draw electronic configurations?
- each circle you surround the nucleus with represents an energy shell and then on each shell you fill it with the number of electrons for that energy level
- represent electrons with crosses
How do you work out the electronic configuration from its period and group?
- period- tells you the number of shells
- group- tells you the number of electrons in the outermost shell
On the periodic table where is the split between metals and non metals?
REMEBER Al-Po B-At
-to the right there is non-metals to the left there is metals
What are general property rules about metals?
- conduct electricity
- metal oxides are basic (they will neutralise acids, they are alkaline)
What are the general property rules for non-metals?
- poor conductors of electricity
- non-metal oxides are acidic (they will neutralise bases, they are acids)
what are the properties on noble gases and why do they have these properties?
-they are inert (very unreactive), because they have a full outer shell so they don’t need to gain or loose electrons (they are stable)
Define ions:
Ions are charged particles (they can be single atoms or groups of atoms)
Why do atoms gain or loose electrons to form ions?
To get a full outer shell
-atoms with full outer shells are stable
Chemical formula for Silver: (and charge)
Ag (charge +)
Chemical formula for Iron(II): (and charge)
Fe (charge 2+)
Chemical formula for Copper: (and charge)
Cu (charge 2+)
Chemical formula for Iron(III): (and charge)
Fe (charge 3+)
Chemical formula for Lead: (and charge)
Pb (charge 2+)