C2.1 Structure and Bonding Flashcards
What is formula of a chloride ion?
Cl-
Why do ionic compounds have high melting and boiling points?
They have strong electrostatic attractions between oppositely charged ions. These take a lot of energy to overcome so they have high melting and boiling points.
How many electrons can go in the second and third electron shells?
8
What is ionic bonding?
It is where a metal and non-metal bond by transferring electrons from the metal to the non-metal.
What type of substance forms negatively charged ions?
A Non-metal
What is an ion?
An ion is a charged atom.
What is the formula of sodium ion?
Na+
Why do simple covalent molecules have low melting and boiling points?
The forces of attraction between molecules (intermolecular forces) are weak so do not require much energy to overcome them.
An element has atomic number 17. What is its electron arrangement?
2,8,7
Are the melting points of giant covalent substances very high or very low?
Very high as it takes a lot of energy to break the strong covalent bonds in the lattice.
A metal ion loses 2 electrons what charge does it have?
+2
Does diamond conduct electricity?
No, as it has no free electrons since each carbon atom forms 4 bonds.
What type of substance loses electrons and forms positively charged ions?
Metals
What is the overall charge of an ionic compound?
0
What are the ions held in place by?
Strong electrostatic attractions between oppositely charged ions.
An element has an electron arrangement of 2,8,8 which group is it in?
It is in group 0 or group 8 as it has a full outer shell.
Why do ionic compounds not conduct electricity when solid?
The ions are not free to move.
Which type of substances bond covalently?
Non-metals only.
A non-metal atom loses one electron. What is the charge on the ion formed?
-1
Give three examples of giant molecular substances
Silicon dioxide ( sand), diamond, graphite
Whats the difference between ionic and covalent bonding?
Ionic bonding is the transfer of electrons whereas covalent is the sharing of electrons.
Why do noble gases not form compounds easily?
They have full outer shells of electrons.
Give three examples of simple covalent molecules.
Water, carbon dioxide and methane
How many electrons can go in the first electron shell?
2
What are the typical properties of ionic substances?
They have high melting and boiling points and conduct electricity when molten or in aqueous solution.
When do atoms turn into ions?
When they lose or gain an electron.
What happens when a metal and non- metal ionically bond?
The metal transfers electrons to the non-metal and becomes positively charged. The non-metal becomes negatively charged.
An element has atomic number 8 what is the electron arrangement?
2,6
Are the melting points of ionic substances very high or very low?
High
Why does graphite conduct electricity?
Each carbon atom only forms 3 bonds instead for 4. So it has delocalised electrons between the layers of carbon atoms which are free to move and pass a current.
True or false? Graphite is softer than diamond.
True, this is because graphite has layers of carbon atoms that can slide over each other easily as they are only held together by weak intermolecular forces.
