First 204 words of the document:
Lesson 1 Structure And Bonding Atomic Structure
The nucleus at the centre of an atom contains two types of particles, called protons and
neutrons. Protons have a positive charge and neutrons have no charge. Electrons are
negatively charged particles that move around the nucleus. An atom has no overall charge,
because the number of electrons is equal to the number of protons and their charges are
equal and positive.
All atoms of an element contain the same number of protons. This number is called the
atomic number (or proton number) of the element. Elements are arranged in order of their
atomic number in the periodic table. The atomic number tells you the number of protons
and the number of electrons in atoms of the element.
1. The nucleus of an atom is made of protons and neutrons
2. Protons have a positive charge, electrons are negatively charges and neutrons have
no charge at all.
3. The atomic number (or proton number) of an element is the number of protons in
the nucleus of an atom
4. Elements are arranged in order of their atomic number in the periodic table