C1-Atomic Structure and the Periodic Table

Page 1

Atoms:

Atoms contain protons, neutrons and electrons.

The radius of an atom is approximately 0.1 nanometers or 1x10(-10) in standard form

Page 2

The Nucleus:

1). The nucleus is in the middle of the atom

2). It contains protons and neutrons

3). The radius of the nucleus is about 1/10 000 of an atom

4). It has a positive charge because of the protons (neutrons have no charge)

5). Almost the entirety of the mass of the atom is concentrated in the nucleus

Page 3

The Electrons:

1). They orbit the nucleus at fixed distances (in electron shells)

2). They are negatively charged and although they are tiny, they cover a lot of space

3). The volume of their orbits determines the size of the atom

4). Electrons have virtually no mass

Page 4

Number of Protons Equals Number of Electrons

Atoms are neutral (they have no overall charge)