#### Electronic Structures

Q1: How many electrons can fit in the first shell?

#### 2

Correct - The first shell is tiny - it's easy to fill.

#### 8

Incorrect - the first shell holds 2 electrons, all other shells hold 8 electrons.

#### 14

Incorrect - the first shell holds 2 electrons, all other shells hold 8 electrons.

#### Electronic Structures

Q2: Fluorine is drawn incorrectly below. Why is it incorrect?

#### It should have 7 electrons in its outer shell

Well done! Fluorine should have nine electrons but only has 8 in the diagram.

#### It should have 8 electrons in the inner shell

Incorrect - The inner shell can only hold 2 electrons.

#### Fluorine has 19 electrons not 8

Incorrect - Fluorine has 9 electrons - it's the smaller of the two numbers (the atomic no.) on the periodic table.

#### Electronic Structures

Q3: Why is the element drawn below incorrect?

#### It should have greater/fewer electrons

Incorrect - Nitrogen has 7 electrons - take a peek at the periodic table to check why.

#### There should be two electrons in the first shell and four in the second

Incorrect - nitrogen has seven electrons

#### There should be two electrons in the first shell and five in the second.

Correct! Nitrogen has 7 electrons, 2 fill up the first shell leaving five for the second shell.

#### Groups, Periods and Electronic Structures

Q4: Look at the element drawn below, which group and period should it be in?

#### Period 6 Group 2

Afraid not - you've got your groups and periods mixed up.

#### Period 2 Group 6

Well done - there are two shells, so oxygen is in period two and the outermost shell contains 6 electrons so oxygen is in group 6.

#### The atom is drawn incorrectly

Incorrect - re-read the information page.

#### Groups, Periods and Electronic Structures

Q5: Name the element that has three electrons in its outer shell and two electron shells.

#### Aluminium

Incorrect - Aluminium is in group 3 however it is in period 3 not 2.

#### Fluorine

Incorrect - Fluorine is in period 2 but it is in group 7.

#### Boron

Correct - well done!.