WHAT DOES AN ATOM LOOKS LIKE ?

 

 WHAT DOES AN ATOM LOOKS LIKE ?

• Protons and Neutrons are held together rather closely in the centre of Atom.
• Together they make up the Nucleus,which accounts for Nearly all of the Mass of the Atom.
• Electrons move rapidly around the Nucleus and constitute almost the entire volume of atom.
• Quantum mechanics are required to explain the motion of an electron about the nucleus, we can say that the Distribution of Electrons about an atom is such that the distribution of electrons about an atom is such that the atom has a spherical shape.                  

• Atoms have sizes on the order of 1-5 Armstrong(1 armstrong = 1A = 1 x 10 power -10 m) and Masses on the order of 1-300 Armstrong(a.m.u)
• The Mass and dimension of the Atoms into perspectively consider the following analogies.
• If an only be the size of ohion stadium,the nucleus would only be the size of small marble.however, the mass of that marble would be ~115 million tons.               

 WHAT HOLDS AN ATOM TOGETHER?

• The Negatively charged electron is attracted to the positively charged nucleus by a columbic Attraction.
• The Proton and Neutrons are held together in the Nucleus by the Strong Nuclear Forces.

HOW MANY ELECTRONS,PROTONS AND NEUTRONS ARE CONTAINED IN AN ATOM?

• Atoms in their nautral state have no charge that is they are neutral. Therefore, in a neutral atom the Number of Protons and Electrons are the Same.If this condition is voilated the Atom has a Net charge and is called an Ion.
• The Number of Protons in the Nucleus determines the identity of the  Atom. For example, All Carbon Atoms contain six protons, all gold Atoms Contains 79 Protons, and  all leads atoms contain 82 protons.
• Two atoms with the Same Number of Protons, but different numbers of Neutrons  are called Isotopes.

HOW DOES THE STUCTURE OF THE ATOM RELATED TO ITS PROPERTIES?

• Chemical Reactions involve either the Transfer or the Sharing of Electrons between Atoms.
• Therefore, the chemical reactivity/properties of an element is primarily dependent upon the Number of Electrons in an atom of that Element .
• Protons Also play a Significant Role because the Tendency for an atom to either Lose or Gain or Share electrons is dependent upon the charge of the Nucleus.
• Therefore,we can say that the Chemical Reactivity of an atom id dependent upon the Number of Electrons and Protons, and independent of the Number of Neutrons.
• The Mass and Radioactive properties of an atom are Dependent upon the Number of Proton and Neutrons in the Nucleus.

NOTE: The Number of protons, Neutrons and Electrons in an Atom completely determine its properties and identity, regardless of how and where the atom was made. So, it is inaccurate to speak of synthetic atoms and natural atoms. In other words, A lead Atom is lead Atom, it does not matter if was mined from the Earth, produced in a Nuclear Reactor, or came to the Earth on an Asteroid.

SYMBOLISM

• There is a Symbolism or shorthand for Describing atoms which is Universally used across all Scientific Disciplines
• Atomic Number (Z) The # of Protons
• Mass Number (A) [The # of Protons]+[The # of Neutrons]
• The number of Protons, Neutrons and Electrons in an Atom are Uniquely specified by the Following symbol example diagram

• where X = The Element symbol (i.e; C,N,Cr) defines the # of Protons. 

•  A = The Mass Number [# of protons]+[# of neutrons]

•  Z = The Net Charge [# of Protons]+[# of Electrons]