Define the number of electrons on the outer shell of the atoms in the following elements: - a) 13 Al 2e 8e … - b) 17 Cl 2e 8e … - c) 20 Ca 2e 8e 8e … 3. Look at the periodic table. How many electron s

Define the number of electrons on the outer shell of the atoms in the following

elements:

- a) 13 Al 2e 8e …

- b) 17 Cl 2e 8e …

- c) 20 Ca 2e 8e 8e …

3. Look at the periodic table. How many electron shells are there in:

- a) the 7 th element

- b) the 10 th element

- c) the 16 th element

- d) the 20 th element

4. Which elements have the following electron configurations?

- a) 1s 2 2s 1

- b) 1s 2 2s 2

- c)1s 2 2s 2 2p 3

- d) 1s 2 2s 2 2p 6