Task 1: Fundamental features of atoms
1. (a) Use the symbols below to explain the nuclear model of the atom:
204Pb 206Pb 207Pb 208Pb 82 82 82 82
A atom is the basic unit of an element .it is a form of matter which cannot be broken down any further .an atom consist of sub atomic particles which are protons, neutrons and electrons .I will be looking at specifically the atom lead. Every element in the Periodic Table has been given a letter symbol , the symbol for lead is Pb.i will now describe the sub atomic particle in lead .protons are in the nucleus of the atom , All atoms of the same element have the same number of protons. This number …show more content…
They have a negative charge of -1 , and there so light that their weight is usually ignored .atoms are electrically neutral , this is due to the fact that the number of protons are the exactly the same as the number of electrons .electron are organised around the nucleus in different energy levels or shells . each shells can only hold a certain number of electrons. The first shell (which is the innermost shell or the lowest energy level ,it is filled first ) can only hold 2 electrons and the second shell can hold 8 electrons ,like wise third shell can hold 8 electrons .The organisation of these energy levels is what gives the elements there different reactivates, the number of electrons in the outer most shell of the atom ,tells you what group it is the periodic table .members of the same group in the periodic table have similar reactivates.
1.b) The atomic mass refers to the mass of one isotope of lead (the total number of protons + the total number of neutrons in the atom ) in this case for lead it is ( 208Pb) 208. 82
, and it is fundamentally different from relative atomic mass, which refer to the weighted average of all the atomic masses of the isotopes of lead and one atomic mass unit (amu) is equal to 1/12 of the carbon-12 …show more content…
It is calculated as the sum of the mass of each constituent atom multiplied by the number of atoms of that element in the molecular formula. were by the relative molecular mass is all the relative atomic mass added together. If all the individual atomic masses of all the atoms in a formula are added together you have calculated the molecular mass .
2 A ) calculate how many moles of water (H_(2 ) 0 ) there would be in 200 g
Number of moles is calculated by the formula, mole = (mass of substance (grams))/(relative molecular mass/relative) (200 g)/(( 1.0079×2)+ (15.999)) = 11.102 mol
No of moles = 11.102