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# Atomic Structure Assignment Help

## Atomic Structure

❶Calculate the wavelength of the second spectral line in Balmer series.

## Various Particles Present in the Diagram of an Atom Structure

Later in the nineteenth century, and at the beginning of the present century, ideas about atomic structure began to develop. Thus, Rutherford concluded that the atom of an element consisted of a positively charged nucleus, containing most of the mass, surrounded in some way by electrons which all together had a negative charge equal to that of the nucleus but possessed little weight.

A few years later, Bohr was able to show that the electrons must be placed in groups, each group having a definite energy. Passage of an electron from one orbit, the greater the energy. One atom of any element always contains the same number of electrons. To balance their charge, the nucleus of that atom must always contain the same amount of positive charge.

But the nucleus is now considered to be made up of protons and neutrons; the proton has a charge equal and opposite to that of the electron, but the neutron has the mass equal to that of a proton but no charge. The simplest atom, hydrogen, has one electron. The nucleus of hydrogen consists of one proton. But it it is equally possible to have an atom with one electron, and having in its nucleus one proton balancing the charge on the electron and one neutron.

Such an atom does in fact exist; it is that of deuterium, and obviously it will weigh more than an atom of hydrogen. Protons are times greater than the electrons. The proton structure is discovered by the scientist named Ernest Rutherford. The electrons are having the negative charges. The electrons cannot able to split into the further particles.

The electrons move freely in the diagram of an atom. The electron forms the electron clouds. The charge of the neutron present in the atom is having neutral charge. The neutrons present in the atom are used to represent the isotope of the element.

Metals are large structures of atoms, in which these atoms are bonded to each other by strong metallic bonds. In this atomic structure one metal is surrounded by the different number of atoms, the number of atom surrounded by particular atom is called as coordination number. Metal has 12, 8, 6 co-ordination number. All the properties of metals are depends on the metal atomic structure. The different properties of metals are given as follows: The boiling and melting points of metals are very high.

This is because of the strength of the metallic bond. The strength of metallic bond is different for different metals. It also depends on the number of electrons which each atom delocalizes into the ocean of electrons.

It means that melting and boiling points depends on metal atomic structure. The atomic structure of metals is responsible for this property, electrical conductivity. In three-dimensional space, the delocalized electrons of the metal are free to move and even they can cross boundaries. Liquid metals are also good conductor of electricity. Therefore, electrical conductivity of metal depends on metal atomic structure.

This decides up to how much power any metal conduct electricity. The atomic structure of metals also gives the information that metals are very good conductors of heat. The electrons pick up the heat energy as the additional kinetic energy and hence, the electrons move faster. Thus, the heat energy is to the whole metal by the movement of these electrons. Metals are termed as malleable, i.

Atomic structure of metal can explain this property. Atoms in the metals can roll over one other into new positions with no breaking of any metallic bond. In , Neils Bohr proposed a model of an atom based on the Planck's quantum theory of radiation. The basic postulates of Bohr's theory are:. Bohr's atomic model explained successfully: The stability of an atom. Bohr postulated that as long an electron remains in a particular orbit it does not emit radiation i. Hence it does not become unstable.

The atomic spectrum of hydrogen was explained due to the concept of definite energy levels. It can absorb a definite amount of energy and jump to a higher energy state. This excited state being unstable, the electron comes back to a lower energy level. When the energy emitted during transition, strikes a photographic plate, it gives its impression in the form of a line.

For example, if the electron jumps down from the third to the first energy level having energies E 3 and E 1 respectively, then the wavelength of the spectral line would be. Similarly, when the electron jumps down from the fourth to the first energy level having energies E 4 and E 1 respectively or from the fifth to the second i.

These will give different lines in the spectrum of the atom corresponding to different transitions having definite wavelengths.

Different lines depending upon the difference in energies of the levels concerned can be summarized in the form of series named after the scientists who have discovered them.

The energy expression for hydrogen like ions such as He, Li can be written as:. Although Bohr's model successfully explained the stability and the line spectrum of hydrogen, it had its limitations.

If the energy difference between the electronic states of hydrogen atom is The frequency n of emitted light is related to the energy difference of two levels D E as. Calculate the wavelength of the second spectral line in Balmer series. In , de Broglie's suggested that all material objects including an electron have a dual character; they behave as particles as well as waves. The wavelength associated with a particle of mass 'm', moving with velocity 'v' is given by de Broglie's relation as:.

The discovery of the wave like character of the electron helped in the making of the modern electron microscope. Heisenberg, in pointed out that it is not possible to measure simultaneously both the momentum or velocity and the position of a microscopic particle with absolute accuracy. Mathematically this may be expressed.

## Main Topics

Sep 06,  · Atomic structure homework help. Parents of ADHD Children:Homework Strategies that EVERY Parent needs - Duration: The History of Atomic Chemistry.

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The Atomic Structure chapter of this AP Chemistry Homework Help course helps students complete their atomic structure homework and earn better grades. This homework help resource uses simple and fun videos that are about five minutes long.