3.3- METALLIC BONDING

Question 1

What are metals?

Answer 1

shiny elements made up of atoms that can easily lose up to three outer electrons, leaving positive metal ions

Question 2

What can atoms in a metal element not do?

Answer 2

transfer electrons

Question 3

When can atoms of an element transfer electrons?

Answer 3

if there’s a non-metal atom present to receive them

Question 4

What happens to the outer main levels of a metal element?

Answer 4

outer main level of atoms merge

Question 5

What does it mean for the outer electrons as the outer main level of atoms merge in a metal element?

Answer 5

outer electrons no longer associated with any one particular atom

Question 6

What is a simple picture of metallic bonding?

Answer 6

metals consist of a lattice of positive ions existing in a “sea” of outer electrons

Question 7

What is the “sea” of electrons described as?

Answer 7

delocalised electrons

Question 8

What does delocalised electrons mean?

Answer 8

they’re not tied to a particular atom

Question 9

What do the positive ions tend to do to one another?

Answer 9

positive ions tend to repel one another

Question 10

What is the repulsion of the positive ions balanced by? (metallic bonding)

Answer 10

electrostatic attraction of positive ions for negatively charged “sea” of delocalised electrons

Question 11

What does the number of delocalised electrons depend on? (metallic)

Answer 11

depends on how many electrons have been lost by each metal atom

Question 12

Where does the metallic bonding spread throughout?

Answer 12

spreads throughout so metals have giant structures

Question 13

What can delocalised electrons do?

Answer 13

move throughout the structure

Question 14

As electrons are able to move throughout the structure, what does this explain in metals?

Answer 14

why metals are such good conductors of electricity

Question 15

From where does the electron join the electron sea?

Answer 15

electron from the negative terminal of the supply joins the electron sea at one end of a metal wire while at the same time a different electron leaves the wire at the positive terminal

Question 16

Why are metals good conductors of heat?

Answer 16

they have high thermal conductivites

Question 17

What is partly responsible for metals having a high thermal conductivity?

Answer 17

sea of electrons is partly responsible for this, with energy also spread by increasingly vigorous vibrations of closely packed ions

Question 18

In general what does the strength of any metallic bond depend on? (2)

Answer 18

charge of ion

size of ion

Question 19

How does charge of the ion affect the strength of the metallic bond?

Answer 19

greater the charge on ion, greater the number of delocalised electrons + stronger the electrostatic attraction between positive ions and electrons

Question 20

How does size of the ion affect the strength of the metallic bond?

Answer 20

smaller the ion, closer the electrons are to positive nucleus + stronger the bond

Question 21

What do metals tend to be? (strength)

Answer 21

strong

Question 22

What explains the metals being strong?

Answer 22

delocalised electrons

Question 23

How do the delocalised electrons explain why metals are strong?

Answer 23

extend throughout solid so there are no individual bonds to break

Question 24

What is it called when metals can be beaten into shape?

Answer 24

metals are malleable

Question 25

What is it called when metals can be pulled into thin wires?

Answer 25

metals are ductile

Question 26

After a small distortion of a metal how is the shape retained?

Answer 26

each metal ion still in exactly the same environment as before so shape retained

Question 27

Do metals have a high or low melting and boiling points?

Answer 27

high melting and boiling points

Question 28

Why do metals have a high melting and boiling points?

Answer 28

they have giant structures

Question 29

What is there between the metal ions and the delocalised sea of electrons?

Answer 29

strong attraction between metal ions and delocalised sea of electrons

Question 30

What is made difficult as there is a strong attraction between the metal ions and delocalised sea of electrons?

Answer 30

makes the atoms difficult to separate