С1
end-of-chapter test
chapter 4 higher
activate
11 amra made up a 100 cm solution of hydrochloric acid and calculated how many acid
particles were in it. she then divided the solution equally into two clean beakers and
used water to make each beaker up to 100 cm.
explain what has happened to the concentration of the solution amra first made.
(3 marks)

the awnser is group 12

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.  

the answer is symmetrical : )