Prep 2
Name:________________________
!. For each of the following elements, calculate how many neutrons are in the
nucleus (Hint: No. of neutrons = Mass no. – atomic no.).
Element
Helium
Beryllium
Carbon
Oxygen
Neon
No. of neutrons
Element
Magnesium
Silicon
Sulphur
Argon
Calcium
No. of neutrons
2. What is the maximum number of electrons can be fitted in each of the following
shells?
a) First shell:
b) Second shell:
c) Third shell:
3. Complete these diagrams using crosses or dots to show the electron
configurations of the following elements:
Hydrogen
Sodium
Chlorine
Calcium
4. Write, using the number and comma notation (e.g. 2,8,1), the electron
configurations of the first 10 elements in the Periodic Table.
5. How many electrons does sodium (Na) have in it’s outer shell?
6. What group of the Periodic Table is sodium in?
7. How many electrons does a sodium atom lose to have a full outer shell?
8. What would the new electron configuration be of a sodium atom that has lost its
outer electron?