UNIT 1: THE ATOMS

WHAT IS MATTER?

Matter is everything that has or causes: Dimensions: Matter occupies space. It has volume.

(m3) Inertia: This property keeps the body still or in

motion. The larger the mass, the greater is the inertia. (Kg)

Gravitational attraction: Bodies attract each other because of gravity.

A material system is anykind of matter whose limits are undefined. Ex: Clouds.

A body is anykind of matter whose limits are defined. Ex: A ball.

BODIES AND MATERIAL SYSTEMS

Natural science studies from tiny things (bacteria) to huge things (stars).

Scientist use two scales: A macroscopic scale: to measure things that can be

perceived using our senses. A microscopic scale: to measure things like cells or

atoms.

SCALES OF OBSERVATION

It’s a way of writing numbers to avoid writing too many zeros.

It consists of writing using powers of ten.

Ex: 100.000.000.000.000.000.000.000.000= 1026

0’000000000000001= 10-15

SCIENTIFIC NOTATION

All matter is made up of very tiny particles called atoms. (10-10 m)

Atoms are the smallest part of any substance. Atoms are made up of:

A nucleus: protons (+) and neutrons.(0) Electrons (-) around the nucleus.

There is nothing but empty space between the electrons and the electrons.

COMPOSITION OF MATTER: THE ATOMS

Chemical element: All the atoms are the same kind. It is represented by a chemical symbol included in the periodic table. Example: Carbon (C)

The pure substances can be: Elements: They have only one type of atom that

cannot be broken down. Ex: O2, H2

Compounds: There are two or more different atoms joined together. Ex: Salt (NaCl), water (H2O)

Atoms join together to form molecules. Ex: CO2 (Carbon dioxide), O3 (Ozone)

TYPES OF SUBSTANCES

Can be

Found in nature as

Found in nature as

1. What is matter? What are the characteristics of matter?

2.What is the difference between a material system and a body?

3. Give an example of inertia in everyday life.4. Identify the elements that form these pure

substances.a)Glucose: C6H12O6

b)Ammonia: NH3

5. Indicate whether these substances are found in nature as atoms, molecules or crystals: helium, water, sodium chloride.

ACTIVITIES

6. In your notebook fill in the blanks using the following words: gravitational, inertia, universe, energy, dimensions, matter.

The…………… can be described in terms of…….. and…….. Matter is everything that has……., ……… and is the cause of ………. attraction.

7. Indicate whether these pure substances are elements or compounds:

a) Water b) Oxygen c)The carbon in a pencil d)The phosphorus in a match.8. Classify the following as bodies or material

systems:a)A ball b) A galaxy c) The water in a river d) The air in the atmosphere