C2-Elements, Compounds and Mixtures Flashcards
1.)Out line how Mendeleev arranged the elements in his version of the periodic table?
He grouped elements with similar properties were in the same vertical group. He put them in order of their atomic mass. Gaps were left for undiscovered elements.
2.) Say were all the groups are located.
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3.) How many electrons would you expect an element in group 7 to have in its outer shell?
7
4.) What is the maximum number of electrons that each of the first three electron shells will hold.
18
5.)The proton number of aluminium is 13. What is its electronic structure?
2.8.3
6.) What is an ion?
They are charged particles they can be single atoms or groups of atoms.
7.)Why does magnesium form a 2+ ion whilst sodium only forms a 1+ ion?
Magnesium is in group 2 so has to lose 2 electrons to become stable where as sodium is in group 1 so has to lose 1 electron to become stable.
8.) Explain why ionic compounds conduct electricity when molten and dissolved but not when solid.
When they are molten the ions are free to move so can carry an electrical current.
9.)Describe how a covalent bond forms
It is an equal share of a pair of electrons
10.) Describe how ionic bonds form.
Electrons are exchanged between a non metal and a metal.they form strong electrostatic forces of attraction.
13.)Why do simple molecular substances have low melting and boiling points?
They have strong electrostatic forces of attraction but weak intermolecular forces that are easily over come with heat.
14.) why do ionic compounds have high boiling points?
Because they have strong electrostatic forces of attraction which take a large amount of energy to overcome.
