We know that any of the matter has mass and takes up space. It is composed of atoms which are also called as basic building blocks of matter. Atoms are considered as the smallest unit which cannot be chemically subdivided by normal chemical or physical methods. Atom word is derived from ‘atomus’ which means indivisible. Today we know that an atom is mainly consisted of three fundamental particles. These particles are arranged in a certain manner to give a stable atom. Put of these 3 subatomic particles, the mass of electrons is negligible therefore most of atomic mass of the atom is due to mass of protons and neutrons. Protons carry positive charge while electrons carry negative charge. Neutrons are neural particles and do not contribute in the charge of atom. The same number of protons and electrons in an atom makes it neutral as the positive charge is negative charge of the atom. According to Bohr’s model, the negatively charged electrons are arranged in circular paths which are called as orbitals around the nucleus. Nucleus which is placed at the center of the atom contains protons and neutrons. The total number of protons in an atom is called as atomic number which is also equal to the number of electrons in an atom. That is the reason; the atomic number is also used to write the electronic configuration of an atom. For example the electronic configuration of carbon atom is 1s2, 2s1, 2p2. The 3d-model of a carbon atom is as given below;
We can also make the 3d model of a carbon atom with the help of floral wire, 6 small styrofoam balls with 12 medium styrofoam balls. First paint 6 medium size balls with same color as all the protons of the atom must be of same colour such as orange.
Now take remaining 6 medium size balls and paint them with blue colour to show neutrons. Take 6 small balls and paint them with green colour. Mark ‘+’ charge on orange balls to show charge on protons and ‘-‘ on green balls of electrons with the help of marker.
Remember protons and neutrons must be of same size and electrons must be small size. Carbon atom contains 6 electrons with 6 protons and 6 neutrons in nucleus. Take a construction paper and cut it in circular shape which must be large enough to hold all 18 balls. Now attach 6 balls of protons and 6 balls of neutrons to both sides of the construction paper with the help of craft glue and form a nucleus of the atom.
Now hang the nucleus with the help of thread and a needle and a large knot is tied at the end. The needle has to run through the construction paper top and then the other end of the fishing line is tied to the bottom of a wire clothes hanger. Then the floral wire is bent into a circular shape and all the six small balls are pierced onto one end of the wire. Now spread all electrons evenly to model orbiting electrons and the two ends of the wire together is twisted so that the balls do not loosen up and make into a close circle of orbit.