Dr. El – Fandy in "Islam and Science", book III says:
The atom is the smallest particle of matter which can exist alone or enter into chemical reactions¼..A small drop of liquid water may contain ten thousand billions of atoms, so that atoms are invisible by the naked eye.
It was believed that the "atom" was the smallest particle, and nothing was smaller in bulk or weight. But modern science has proved that, that insignificant thing which the eye cannot see is but liable to division.
Mr. Kamel Abd El-Samad in his book says that by the end of the 19th and the beginning of the 20th, centuries scientists discovered that atoms of some materials like radium and uranium possess the quality of self division, and come out of them electropositive small particles called "Alfa", as well as small electronegative particles called "Beta", rays that are called "Gamma" rays.
He goes on saying that in January 1939 scientists succeeded in breaking the "atom", German scientists in the Berlin Institute were able to split the uranium atoms into two parts and other smaller parts.
More than 1400 ago the Holy Qur'an states clearly that the atom has a weight and it could be divided. Hence we can see again that the Holy Qur'an is ahead of science. God says:
Surely God shall not wrong so much as the weight of an ant and if it be a good deed
He will double it, and give from Himself mighty wage. (Qur’an 4:40)
And not so much as the weight of an ant* in earth or heaven escape from thy Lord, neither is aught smaller than that, or greater, but in a Manifest Book. (Qur’an 10: 61)
And whoso has done an atom's weight of good shall see it, and whoso has done an atom's weight of evil shall see it (Chapter 99)
*N.B. In the first two translations Mr. Arthur J. Arberry followed an obsolete interpretation of the word "ذرة", when men could only imagine nothing smaller than an ant. While in the third verse he correctly translates the word "ذرة" into "atom" which is the correct translation.