C1-Atomic Structure and the Periodic Table

Atoms:

Atoms contain protons, neutrons and electrons. The radius of an atom is approximately 0.1 nanometers or 1x10(-10) in standard form  

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

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

Number of Protons Equals Number of Electrons

Atoms are neutral (they have no overall charge)