Matter and Atoms


Atom is the smallest unit of matter that is composed of a nucleus surrounded by electrons. The atomic nucleus contains protons, positively charged, and neutrons with zero charges.

In the atom, every proton has a positive charge +1, and the electrons around the nucleus have a negative charge of -1.

Protons and Neutrons have a similar mass of 1.67×10-27 kg and 1.69×10-27 kg respectively, which is around 1836 times the weight of the electrons at 9.11×10-31 kg.

The electrons are attracted to the protons by electromagnetic forces, but they have properties of a particle, spinning around their own axis, and a wave, which defines a region where they can be found around the nucleus, called Orbital.

Orbitals can have one or more rings or node structures, and they differ from each other in size, shape and orientation. The first two electrons are located in the spherical orbital 1s, a third electron will be in a bigger orbital as the 2s.