topic 1.2 periodic table

Question 1

How did dmitri Mendeleev arrange elements known in 1869

Answer 1

First arranged in groups useing properites
Realised if put in order of atomic mass, a pattern appeared and put elements with similar properties in columns.
Some elements seemed to be in wrong column so Dmitri left a gap.

Question 2

How did Dmitri use his table to predict undiscovered elements’ properties

Answer 2

Using the properties of elements in the column

Question 3

why might Mendeleev table of increasing atomic mass structure might not always be true

Answer 3

Because of the relative abundance of isotopes and relative atomic mass of the element.

Question 4

what is electronic configuration

Answer 4

e.g. magnesium atomic number 12
2.8.2

Question 5

hwo is electronic configuration related to position in periodic table

Answer 5

last number shows the column
number of digits e.g. 2.8.2 =3 = period 3
number of digits same as period