Atomic Structure Assignment (Question 1-answer)

Q1)What does an atom looks like? What are the sub-atomic particles inside it.....(talk about electrons, neutrons, protons, electron shells, nucleus....)

An atom looks like a nucleus surrounded by electron shell(s). The sub-atomic particles are protons, neutrons and electrons. Protons and neutrons can be found in the nucleus. Electrons are found in its electron shell. Protons are positive (+1 charge) with a relative mass of 1, neutrons are neutral with a relative mass of 1 while electrons are negative (-1 charge) with a relative mass of roughly 1/1836.

Mass number/ Nucleon number/ Ar (relative atomic mass) : protons = neutrons
Proton number=Atomic number
No. of electrons=No. of protons
No. of neutrons=Nucleon number-no. of protons

Image credits to: http://www.suite101.com/content/atoms-the-smallest-part-of-all-elements-a137985