chem Flashcards
changes in states of matter
solid to liquid -melting
liquid to gas - evaporation
gas to liquid -condensation
liquid to solid - freezing
solid to gas - sublimation
gas to solid - deposition
which energy shells are closest to the nucleus
the lowest energy shells
Electronic configuration
- periodic table tells you the atomic number of e.g nitrogen= 7
- so it has 7 protons and 7 electrons
- by following the rule above: the first shell holds a maximum of 2, and the remaining 5 go in the second shell
- so the electronic configuration is 2,5
How else can you work out the electronic configuration?
from its period and group
- the period number is equal to the number of shells occupied
- the group number is equal to the number of electrons in the outer shell
what produces ionic compounds
transfer of electrons
Ionic bonding
1) when a metal and non-metal react together, e.g. group 1 metals react with group 7 elements, the metal atom looses electrons to form a positive ion (cotion) and the non-metaal gains these electrons to form a negative ion (anion).
2) these opposingly charged ions are strongly attracted to one another by electrostatic forces. this is called an ionic bond
3) the reaction of sodium and chlorine is a classic case of ionic bonding.
ionic bonding example:
Sodium chloride
The sodium atom gives up its outer electron and becomes an Na+ ion
The chlorine atom picks up the spare electron and becomes a Cl- ion.
properties of metals
which elemenr is not reactive from the ones shown
noble gas.
because it has a full outer shell and it doesn’t react with anything else
find relative atomic mass equation
calculate average atomic mass of chlorine if its abundance nature is 75.77% 35cl and 24.33 37cl
35x75.77 + 37x24.23/ 100
why are ammonia particles close to the hydroxide
because they particles arwe lighter which means they move faster
when alkali metals reract with water they form a ametal hydroxide and oxygen
2(m) +2H20 arrow 2(m)OH +H2
m is the metal eg Na, Li, K
