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#ELEMENTS TABLE WITH ATOMIC MASS AND ATOMIC NUMBER HOW TO#

We shall discuss about these, in detail, in our later posts.

In Chemistry, there are different types of radii we consider according to the type of species under study –.

It’s as if the love/attraction(electrostatic) between protons and electrons increases and thus they all keep coming closer together, resulting in decrease in atomic radii.

electrostatic force of attraction between protons in the nucleus and electrons increases as atomic number increases.Īcross a period, atomic number increases ⇢ # of protons increases ⇢ # of electrons increases ⇢ the electrostatic force between them also increases.

Atomic radii decreases from going from left to right across a period as –.

– Group 1 Li,Na,K ,Rb,Cs,Fr atomic size increases down the group (See figure below).

Atomic radii increases down a group as every time a new valence shell is added around the nucleus as a result of increasing atomic number.Į.g.

Also, we know that orbitals are nothing but spaces where the probability of finding electrons is the highest.So, we have to consider an arbitrary edge for the valence atomic orbitals.

So the nucleus is like a pea in the middle of the racetrack or a spec of dust in a very large room ! So, the nucleus is 1/100000 th times smaller than the atom. Size of the atom = 10 -10 mi.e 10000000000 atoms would approximately fit in 1 meter distance. Whether one measures the distance from the centre of the nucleus or from the circumference is immaterial, as the size of the nucleus is negligibly small compared to the size of the atom.

In general ,atomic radius is the distance from the nucleus to the outermost occupied shell of the atom.

e.g.- 35Cl and 37Cl are isotopes of chlorine having atomic mass numbers 35 and 37 respectively. So, we can conclude that isotopes of an element have the same atomic number but different atomic mass number.

#ELEMENTS TABLE WITH ATOMIC MASS AND ATOMIC NUMBER HOW TO#

( NOTE – How to remember this? Alphabetically A is always at the top and Z at the bottom.Similarly, the mass number(A) is written at the top and the atomic number (Z) at the bottom). The atomic number(Z) is written as a subscript and atomic mass number(A) is written as superscript, to the left of the element symbol. This quantity gives us the number of protons and neutrons in the nucleus of an atom.As the atomic number increases with each element in the periodic table, so does the atomic mass number. As seen above the three different isotopes of hydrogen have the same atomic number but their atomic mass number distinguishes them from one another.

Atomic number gives an element its chemical identity. Atomic number is the most fundamental property, as it dictates the properties an element possess.

We have already studied that ‘the properties of elements are periodic functions of their atomic numbers’. The elements are arranged in increasing order of their atomic numbers in the periodic table. It can also be defined as the number of electrons in a neutral atom.Į.g.– Atomic number of hydrogen is Z = 1, as it contains only 1 proton.Deuterium, tritium which are isotopes of hydrogen also have the same atomic number as the number of protons in their nucleus remains the same (although number of neutrons is different).

The arrangement of elements is such that their properties show a periodic trend across a row and down a group.Let us start studying the various properties of elements, which gives the arrangement of elements in the periodic table a beautiful pattern.Ītomic number (Z) is the number of protons found in the nucleus of an element. We shall begin our discussion on the general periodic trends of the periodic table from this post onwards.Periodicity means the tendency to recur/repeat at regular intervals.The table of elements manifests this phenomenon in many ways.