The Periodic Table

Question 1

how did mendeleev arrange the periodic table

Answer 1

in order of relative atomic mass

Question 2

what did mendeleev also realise about the atomic mass of the elements

Answer 2

that the physical and chemical properties of elements were related to the atomic mass in a periodic way

Question 3

how did mendeleevs realisation of the atomic mass change how he structured the table

Answer 3

caused him to arrange the table in a way that groups of elements, with similar properties, fell into vertical columns

Question 4

how did mendeleev predict the properties and existence of elements yet to be discovered

Answer 4

• he had gaps in his periods, so he assumed elements hadnt been discovered.
• due to there being a pattern with the atomic masses on the table, he was able to predict the atomic masses of the unknown elements
• so he could predict their properties

Question 5

how were mendeleevs ideas supported by later science

Answer 5

we could weigh the atoms to prove the increasing atomic mass resulted in the increase of mass

Question 6

what are some of the problems mendeleev had when ordering the elements

Answer 6

• because he tried ordered them in order of atomic mass and their properties, he broke his own rules
• for example, he put iodine after tellurium to group it with its similar elements even though iodine has a lower atomic mass than tellurium

Question 7

how are elements arranged in the modern periodic table

Answer 7

by the atomic number (protons) instead of atomic mass

Question 8

what is electronic configuration

Answer 8

the distribution of electrons of an atom

Question 9

how would you present the electronic configuration of magnesium in numbers

Answer 9

2.8.8.6

Question 10

what can the groups represent in the periodic table in relation to the subatomic particles

Answer 10

the number of electrons in its outer shell

Question 11

why isnt hydrogen ‘inside’ the bulk of the periodic table

Answer 11

• it cant be definitely classified into any group
• the only thing H has in common with alkali metals in group 1 is that it has 1 electron in its outer shell, but its not a metal
• the only thing H has in common with halogens is that its one electron short of a complete shell and exists in gas form, however H is a reducing agent where-as halogens are oxidising agents

Question 12

what is the atomic mass

Answer 12

the neutrons and protons in a nucleus

Question 13

what is the atomic number

Answer 13

the number of protons in a nucleus

Question 14

what is an advantage of the modern periodic table

Answer 14

you can easily work out which elements are metals ad non metals

Question 15

what do elements with similar properties form

Answer 15

the columns (groups)

Question 16

what does the group number tell you and how is it useful

Answer 16

• the number of electrons in the outer shell

- it can be used to predict the reactivity of the atom

Question 17

if you know the properties of one element in a group, what does it allow you to do

Answer 17

predict the properties of other elements in the group

Question 18

how does the reactivity change throughout group one

Answer 18

reactivity increases as you go down the group

Question 19

what does each new period represent in the table

Answer 19

a new full shell of electrons