bonding - ionic and covalent

Question 1

how are ions made

Answer 1

when electrons are gained or lost to form a full outer shell

Question 2

what are ions

Answer 2

they are charged particles - they can be single atoms or groups of atoms

Question 3

what happens when metals form ions

Answer 3

they loses electrons to form positive ions

Question 4

what happens when non-metals form ions

Answer 4

they gain electrons to form negative ions

Question 5

how can you tell the charge on an ion

Answer 5

it is the same as the number of electrons lost or gained
e.g. if 2 electrons are lost the charge is 2+. if 3 electrons are gained the charge is 3-

Question 6

what happens when a metal and a non-metal react together

Answer 6

the metal atom loses electrons to form a positively charged ion and the non-metal gains these electrons to form a negatively charged ion

Question 7

how are these oppositely charged metal and non-metal ions attracted to each other and what is this attraction called
2 points

Answer 7

1) they are strongly attracted to each other by electrostatic forces
2) ionic bonding

Question 8

what is another name for positive and negative ions

Answer 8

1) negative- anions
2) positive- cations

Question 9

draw the dot and cross diagram for sodium chloride (NaCl)
and magnesium chloride (MgCl2)

Answer 9

page 49 chem revision book

Question 10

what are dot and cross diagrams good for and not good for

Answer 10

1) they are good for showing how ionic compounds are formed
2) but they don’t show the structure of the compound, size of the ions or how they’re arranged

Question 11

what structure do ionic compounds have

Answer 11

they have a structure called a giant ionic lattice

Question 12

what similar properties do all ionic compounds have

Answer 12

1) high melting/ boiling points because they have strong bonds between ions
2) when they’re solid, the ions are held in place, so they can’t conduct electricity
3) when ionic compounds melt , the ions are free to move and they’ll carry electric charge
4) some ionic compounds also dissolve easily in water

Question 13

what happens when non-metal atoms bond together

Answer 13

they share pairs of electrons to make covalent bonds

Question 14

what happens to the nuclei of the covalently bonded atoms

Answer 14

they are attracted to the shared pair of electrons by electrostatic forces, making covalent bonds very strong

Question 15

what shell do atoms share their electrons from and why
2 points

Answer 15

1) ones on their outer shell
2) they have the highest energy levels

Question 16

draw the dot and cross diagram for these covalent bonds
1) H2
2) O2
3) N2
4) HCL
5) CH4
6)H2O

Answer 16

look on oage 54-55 of chemistry book

Question 17

what are the properties of simple molecular substances
7 points

Answer 17

1) substances containing covalent bonds usually have simple molecular structures
2) atoms within the molecules are held together by very strong covalent bonds
3) the forces of attraction between these molecules are very weak
4) to melt/ boil these compounds you need to break the weak intermolecular forces, so they have low melting/ boiling points
5) most molecular substances are gases or liquids at room temp
6) as molecules get bigger, the strength of the inter molecular forces increases so the melting and boiling points increase
7) molecular compounds don’t conduct electricity because they aren’t charged so no free electrons