3.1
Everything you can perceive using your senses is called the macro level. To find out what the building blocks of a substance are,
you first must zoom in on the substance and study ever smaller particles of the substance. Eventually you will reach the micro
level, you then study the smallest particles from which a substance is built. When these particles are put together you get a
substance.
The smallest particles in most substances are called molecules. A pure substance consisted of only similar particles. For
example, water consisted only of water molecules. However, the properties of a molecule are different form those of the
corresponding substance. For a substance you can indicate the state, for a single molecule you can’t
In chemistry you continually switch between macro and micro level. Ate the micro level you describe the phases using
observations you make at the macro level.
The stacking in a solid is called a lattice. In a solid the molecules vibrate but they remain in place. At a certain
temperature/melting point, the vibrations are so strong that it breaks the lattice.
In a liquid the molecules disorderly move through.
If a temperature gets even higher/ boiling point the molecules become completely separated. They are now at a large distance
of each other and form a gas.
Something you cannot observe directly, can be described by a model.
A model is a simplified reproduction of reality. Using a model is a way to make reality easier to fathom. You should realize a
model will always distort reality to a certain extent.
A model is for example used to shrink or zoom in on molecules because they can’t be seen with the blind eye.
3.2
You can zoom in on a molecule and see that molecules are made up of even smaller particles. These particles are called atoms.
Therefore, the building blocks of molecules are atoms. Two or more atoms combine to form a molecule. These atoms can be the
same kind or different kinds.
The combination of several atoms stuck together are called a molecule. A molecule that consists only of one kind of atom is
called an element. A molecule that consists of several kind of atoms is called a compound. You can encounter the names
‘’compound’’ and ‘’element’’ at micro- and as macro level.
There are a little over 110 kind of atoms that enable you to make millions of different molecules. Each kind of atom has its own
symbol that consist of 2 letters.
The systematic way in which the symbols of the elements are arranged is called, the Periodic table.
In 1869 Dmitri Mendeleev devised this system in which he clarified a relationship between chemical and physical properties of
elements.
The horizontal rows in the Periodic Table are called periods. The vertical rows are called groups. Several groups you must know:
Group 1: alkali metals, Group 2: alkaline earth metals, Group 17: halogens, Group 18: noble gases.
Periodical table consists of mostly metals, then non-metals and a small group of metalloids.
There are approximately twenty elements that are called non-metals.
A pure metal is a substance with only one kind of atom. Therefore it is an element. There are over 90 elements that we call
metals.
All metals have a number of general properties of substance in common: A shiny surface in their pure form, they conduct heat
and electricity, they are malleable especially when their hot, they can when molten be mixed with other elements.
Many metals will react to substances from their surroundings. In iron this process is called rusting. In other metals its called
corrosion.
Metals are divided in: Precious metals; do not react to oxygen. Semi-precious metals: can react with difficulty to oxygen.
Reactive metals: these react easily with oxygen in the air. Highly reactive metals: these react readily and violently with oxygen
and water in the presence of air.
Everything you can perceive using your senses is called the macro level. To find out what the building blocks of a substance are,
you first must zoom in on the substance and study ever smaller particles of the substance. Eventually you will reach the micro
level, you then study the smallest particles from which a substance is built. When these particles are put together you get a
substance.
The smallest particles in most substances are called molecules. A pure substance consisted of only similar particles. For
example, water consisted only of water molecules. However, the properties of a molecule are different form those of the
corresponding substance. For a substance you can indicate the state, for a single molecule you can’t
In chemistry you continually switch between macro and micro level. Ate the micro level you describe the phases using
observations you make at the macro level.
The stacking in a solid is called a lattice. In a solid the molecules vibrate but they remain in place. At a certain
temperature/melting point, the vibrations are so strong that it breaks the lattice.
In a liquid the molecules disorderly move through.
If a temperature gets even higher/ boiling point the molecules become completely separated. They are now at a large distance
of each other and form a gas.
Something you cannot observe directly, can be described by a model.
A model is a simplified reproduction of reality. Using a model is a way to make reality easier to fathom. You should realize a
model will always distort reality to a certain extent.
A model is for example used to shrink or zoom in on molecules because they can’t be seen with the blind eye.
3.2
You can zoom in on a molecule and see that molecules are made up of even smaller particles. These particles are called atoms.
Therefore, the building blocks of molecules are atoms. Two or more atoms combine to form a molecule. These atoms can be the
same kind or different kinds.
The combination of several atoms stuck together are called a molecule. A molecule that consists only of one kind of atom is
called an element. A molecule that consists of several kind of atoms is called a compound. You can encounter the names
‘’compound’’ and ‘’element’’ at micro- and as macro level.
There are a little over 110 kind of atoms that enable you to make millions of different molecules. Each kind of atom has its own
symbol that consist of 2 letters.
The systematic way in which the symbols of the elements are arranged is called, the Periodic table.
In 1869 Dmitri Mendeleev devised this system in which he clarified a relationship between chemical and physical properties of
elements.
The horizontal rows in the Periodic Table are called periods. The vertical rows are called groups. Several groups you must know:
Group 1: alkali metals, Group 2: alkaline earth metals, Group 17: halogens, Group 18: noble gases.
Periodical table consists of mostly metals, then non-metals and a small group of metalloids.
There are approximately twenty elements that are called non-metals.
A pure metal is a substance with only one kind of atom. Therefore it is an element. There are over 90 elements that we call
metals.
All metals have a number of general properties of substance in common: A shiny surface in their pure form, they conduct heat
and electricity, they are malleable especially when their hot, they can when molten be mixed with other elements.
Many metals will react to substances from their surroundings. In iron this process is called rusting. In other metals its called
corrosion.
Metals are divided in: Precious metals; do not react to oxygen. Semi-precious metals: can react with difficulty to oxygen.
Reactive metals: these react easily with oxygen in the air. Highly reactive metals: these react readily and violently with oxygen
and water in the presence of air.
