C2 Flashcards
How did chemists try to organise elements in the periodic table ?
They tried to find patterns in the behaviour of them
Who was at number one in the development in the periodic table ? What did he discover ?
John Dalton arranged the elements in order of their atomic weights
Who was the second person that contributed to the development of the periodic table ? What did he discover .
In 1864 John Newlands noticed that the properties of every eighth element seemed similar . He produced a table showing his ‘ law of octaves ‘ . However he did not take into account that new elements were being discovered .
Who was the third person to contribute to the development of the periodic table ? What did he discover ?
In 1869 Dmitri Mendeleev also placed them in atomic order of weights . In the table he left gaps for new elements that were being discovered .
What are elements in order of in the periodic table ?
Their atomic numbers
How many groups are there in the periodic table ?
8
Why do elements in the same groups react in similar ways ?
Because they all have the same number of electrons on their outer shell
Do metals conduct electricity ?
Yes
Do non metals conduct electricity ?
No
What are some characteristics of metals ?
They have high melting and boiling points
They are ductile
They are malleable
Low density
Silvery shiny surface when cut
What type of ions do group 1 , 2 and 3 form and why
Positive ions , because an element is giving away electrons .
What ions do groups 5 , 6 and 7 form ?
Negative ions
How many electrons do noble gases have on their outermost shell ?
8
Do the boiling points get higher going down group 8 ?
Yes
How many electrons do alkalis need to lose to gain a stable electronic structure ?
One electron
How does an alkali metal lose its one outer electron ?
By reacting with a non metal
What are the characteristics of group 7 metals ( halogens ) ?
Toxic
Low melting and boiling points which do increase as you go down the group
Poor conductors of heat
Made up of pairs of atoms ( covalent bonding ) , diatomic molecules
Is this true , the number of shells in an atom increases down every group ?
Yes
What is meant when the outer electrons are further away from the attractive force of the nucleas ?
The electrostatic force between them is weaker , this means that electrons in the outer shells of a group like 1 are easily removed and given to a group 7 element .
