§2.1 Molecules and Atoms

• Scheikunde
• Middelbare school
• havo, vwo
• Leerjaar 3

§2.1 Molecules en atoms

Chapter 2: Chemical Reactions

Learning Objectives 2.1.

2.1.1 You know that molecules are made up of atoms.

2.1.2 You can explain the difference between elements and compounds.

2.1.3 You can represent molecules using molecular formulae.

2.1.4 You can give the systematic names of molecules.

2.1.5 You can describe the difference at the micro level between a separation method, a phase transition and a chemical reaction.

Remember the particle model?

 

Chemical Reactions...

Molecules are broken down and new molecules are formed.

A reaction can be written down as an equation or process:

molecules go in (reactants), different molecules come out (products).

 

Het alfabet and the PT:

Alphabet	PT
Letter	Atom/Element
Word	Molecule
Sentence	Substance
Story	Materials

Atoms in a molecule are connected by atomic bonds (bonds between atoms)

Elements in the periodic table

We know about 118 different kinds of atoms, aka 118 elements

Every element has its own name and symbol 

Memorize the names and symbols in table 1!

 

d

Elements

Based on one kind of atom or molecules with one kind of atom (pure)

ggg

g

Compounds

Molecules containing more than one kind of atom.

Molecules can be drawn but they can also be given a molecular formula.

Naming compounds - Nomenclature, systematic

1. First element of compound keeps its own name
2. Second element gets -ide at the end 
3. Greek numbering words are used to indicate how many of each element is in the formula

N2O = dinitrogen oxide                      CCl4  = carbon tetrachloride 

  

Greek:	number
mono-	1
di-	2
tri-	3
tetra-	4
penta-	5
hexa	6

hepta-	7
octa-	8

Name: index comes first

Formula: symbol comes first, followed by index

Never start a name with mono

Practise:

Give the name:

1. N2O5

2. P2I4

3. S2Cl2

Give the formula:

1. phosphorous trichloride

2. dinitrogen monoxide

3. diphosphorous pentaoxide

Element: 

molecules or atoms containing one single type of atoms

Molecule:

more than one atom bonded together 

Atom:

smallest building block of elements/molecules

Compound:

molecules made up of different atoms

Molecules and atoms are very small. If you would mix water (H2O), pure alcohol (C2H6O) and salt (NaCl) in a glass, you would get a clear, transparant solution.

How many types of atoms are in this glass?

1. 1
2. 3
3. 5
4. millions

Molecules and atoms are very small. If you would dissolve a teaspoon of pure sugar mix in a glass of pure water, you would get a clear sugar solution

How many types of molecules are in that glass?

1. 1
2. 2
3. 3
4. miljoenen

compound

element

molecules

H2

CH4

Cl2

HF

C6H12O6

Na

1. separation
2. phase transition
3. reaction

1. separation
2. phase transition
3. chemical reaction

1. separation
2. phase transition
3. chemical reaction

1. separation
2. phase transition
3. chemical reaction

1. separation
2. phase transition
3. chemical reaction

Recap today

2.1.1 You know that molecules are made up of atoms.

2.1.2 You can explain the difference between elements and compounds.

2.1.3 You can represent molecules using molecular formulae.

2.1.4 You can give the systematic names of molecules.

2.1.5. You know the difference between separation, phase transitions and chemical reactions.

 

Homework for next class (march 9)! 

Read chapter 2.1.  

Assignment 1 to 9