This document provides an overview of atoms, elements, molecules, and compounds. It discusses how everything is made up of atoms, which contain subatomic particles like protons, neutrons, and electrons. Atoms of the same element have the same number of protons. Elements are organized in the periodic table according to their properties and atomic structure. Atoms can bond together to form molecules, which are made of one or more elements. Compounds are molecules made of two or more different elements bonded together. The properties of compounds are different from the individual elements.

1. Atoms, Elements,
Molecules and
Compounds
Science 1st ESO
By Ainhoa Aporta

2. Atoms and elements
• Everything is made up of atoms.
• There are over hundred different types of atom.
And each type is called an ELEMENT like iron,
oxygen or carbon.

3. A model of an atom
• Atoms themselves are divided into even
smaller parts called sub-atomic particles.

4. Sub-atomic particles
• Protons and neutrons are the sub-atomic particles
that make up the nucleus of the atom (the centre).
• Protons have a positiv electric charge
• Neutrons have no electric charge.
● Electrons are the sub-
atomic particles that are
orbiting around the
nucleus.
● They are negatively charged.
That’s way they are
attracted by the positive
charges in the protons, being
held in place.

5. Atomic number
• Atomic number: number of protons in the nucleus
of an atom.
• A normal atom has the same number of electrons as
protons. Therefor you can know the number of electrons
in an element looking at its atomic number..

6. Atomic mass
• The atomic mass of an atom depends on the
number of protons and neutrons in the nucleus.
Carbon atomic mass = 6 neutrons + 6 protons = 12

8. Periodic table
• There are 116 known elements, which are organized and
classified in the Periodic Table.
• Each element has its own chemical symbol that is used all over
the world, for example for Oxygen the chemical symbol is O.
• According to their properties elements can be grouped into:
• Metals
• Non-metals
• Each column contains elements which are similar to each other
and is called a group with its number indicated on the top.
• The rows across are called periods.

10. • http://education.jlab.org/itselemental/ele0
01.html
• http://www.bbc.co.uk/worldservice/sci_tec
h/features/elementary/statcon/element2a.
shtml

11. PROPERTIES METALS NON-METALS
Appaerence
Density
Conducts
electricity
Conducts heat
Malleable
Magnetic

12. Molecules
• Atoms bond together to form larger
particles called MOLECULES, and molecules
join together in different ways to produce
the matter and the different
SUBSTANCES.

13. Elements and compounds
• Those molecules which are made from only one
type of atom are called ELEMENTS.
• Those molecules which are made up of different
types of atoms are called COMPOUNDS, such as
the molecule of water.
Oxygen (O2), element made
up of 2 atoms of oxygen.
Water (H2O), compound made
up of 2 atoms of hydrogen and
one atom of oxygen.

16. Investigating compounds
• We can identify which elements are in a
compound by flame testing.
• When you burn metallic elements they make
flames of different colours.

17. • Scientists put a sample of the compound on the end of a wire
loop (previously cleaned).
• The wire is then placed in the flame of a Bunsen Burner.
• The flame changes color depending on the element.

19. Describing molecules-
formulae
• When we describe molecules we
use formulae.
• When working with formulae:
• We use the chemical symbols to
indicate the elements that form the
molecule.
• We add numbers to show how many
atoms of each element are found in
the molecule.

20. Chemical reactions
• Compounds are new substances which get formed
from two or more different elements through a
chemical reaction.
• Their properties are different to the properties of the
elements that make them.
• Example: hydrogen and oxygen react to form water.

21. • Rusting is also an example of a combination
reaction (oxidation):
• Iron (Fe) + Oxygen (O) iron oxide

22. • When in the combination reaction only two
substances are involved, joining together to
form a new compound, the name of the
compound will always end in “ide”.

23. • https://www.youtube.com/watch?
v=kRUbVm21L_U
• https://www.youtube.com/watch?
v=cJ7rzo1wirs
• https://www.youtube.com/watch?
v=FofPjj7v414