Physics Of The Mass Atomic Mass

964 Words Oct 7th, 2015 4 Pages
An atom contains protons, neutrons and electrons; the protons and neutrons are I the nucleus of the atoms and the electrons are in the outer shells of the atoms. There are different charges of protons, neutron’s and electron’s: protons have a positive charge however, neutron have no charges and electrons have a negative charge. The electron shells contain electrons a 8 electrons can make a full outer shell however, the first shell has to always be 2 electrons in it
In addition the periodic table is table that represents elements as symbols e.g. (He) represents helium, each symbol have a number above the symbols and one at the bottom of the symbols
The number at the top represents the relative atomic mass (protons plus neutrons) there is also a number at the bottom of the symbol which represents the number of protons.
How elements are organised in groups periods and blocks
2. Periods
Elements that are arranged in horizontal rows, in the first row all the elements have the same number of shells. As you go across the period an electron adds on the proton number and also electrons as protons and electron are the same, the electron shells stay the same across each period and also and a proton is added in the nucleus.
In addition the elements are arranged in in order of increasing atomic number
The groups are set up in columns each group of elements have their similar chemical properties e.g. in group 1 lithium is the least reactive however as you go down a column…
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