In order to overcome the objections raised against Rutherford’s model of the atom, Neils Bohr put forward the following postulates about the model of an atom: These orbits or shells are called energy levels. Energy levels in an atom are shown in figure.These orbits or shells are represented by the letters K,L,M,N,… or the numbers, … Read more
The physical and chemical properties of the elements repeat periodically with their atomic number.
Methanal or the saturated aqueous solution of formaldehyde (40% by volume, 37% by weight) is known as 100% formalin which is mainly used to preserve dead animals.
Arranging the elements based on their molecular weight, their physical and chemical properties are noticed to periodically reoccur.
Electron configuration is the distribution of electrons in various shells for any element. Such as electron configuration of Al is-Al(13)→ 2, 8, 3
According to Dalton’s atomic theory, the atom was indivisible and indestructible. But the discovery of two fundamental particles (electrons and protons) inside the atom, led to the failure of this aspect of Dalton’s atomic theory. It was then considered necessary to know how electrons and protons are arranged within an atom. For explaining this, many … Read more
Around the nucleus there are some circular stable axis on which electron moves around. These are called energy level or orbit.
Atoms of the same element having different mass number are called isotopes of each other.