Chemistry

The basic particles of an Atom: Protons, neutrons and electrons

What is the radius of an atom? About 0.1 nanometer (1 x 10^-10m)

Where is it? Middle of the atom

Contains: Protons and Neutrons

The radius of the nucleus? Around 1x10^-14m (1/10,000 of the radius of an atom)

why does it have a positive charge? Because of the protons

Where is the mass of an atom concentrated? Nucleus

Where does the electron move around? The nucleus in electron shells

What determines the size of an atom?  The volume of an electron's orbit  

Have almost no mass

Negatively charged and tiny but cover a lot of space

if an atom has the same number of protons and electrons then it would be neutral (have no charge) as they cancel each other out because their charge is the same.