10.1- THE HALOGENS

Question 1

Is the group 7 elements metals or non-metals?

Answer 1

non-metals

Question 2

What do the group 7 elements exist as?

Answer 2

diatomic molecules

Question 3

What is the group 7 elements called?

Answer 3

halogens

Question 4

What is the appearance of the gaseous halogens?

Answer 4

vary in appearance

Question 5

At room temperature what colour and state is fluorine?

Answer 5

pale yellow gas

Question 6

At room temperature what colour and state is chlorine?

Answer 6

greenish gas

Question 7

At room temperature what colour and state is bromine?

Answer 7

red-brown liquid

Question 8

At room temperatue what colour and state is iodine?

Answer 8

black solid

Question 9

Going down group 7 how does the colour and density of the elements change?

Answer 9

get darker and denser going down group

Question 10

What smell does all the halogens have?

Answer 10

“swimming-bath” smell

Question 11

What is a number of the properties of fluorine described as?

Answer 11

untypical

Question 12

Where does many of the untypical properties of fluorine stem from?

Answer 12

F-F bond unexpectedly weak, compared with trend for rest of halogens

Question 13

What is the size of fluorine like?

Answer 13

small size

Question 14

What does the small size of fluorine lead to?

Answer 14

repulsion between non-bonding electrons as they’re so close together

Question 15

How does electronegativity change going down group 7?

Answer 15

decreases going down group 7

Question 16

How does atomic radius change going down group 7?

Answer 16

atomic radius increases going down group 7

Question 17

How does melting point change going down group 7?

Answer 17

melting point increases going down group

Question 18

How does boiling point change going down group 7?

Answer 18

boiling point increases going down group 7

Question 19

Why does the atoms get bigger going down group 7?

Answer 19

because each element has one extra filled main level of electrons compared with one above it

Question 20

What is electronegativity?

Answer 20

measure of ability of atom to attract electrons, or electron density, towards itself within a covalent bond

Question 21

What does electronegativity depend on?

Answer 21

attraction between nucleus + bonding electrons in outer shell

Question 22

What does the attraction between the nucleus + bonding electrons in the outer shell depend on? (3)

Answer 22

depends on balance between number of protons in nucleus (nuclear charge)

distance between nucleus and bonding electrons

shielding effect of inner shells of electrons

Question 23

What happens to the shared electrons in hydrogen halides, HX going down the group?

Answer 23

get further away from nucleus as atoms get larger going down group

Question 24

As the shared electrons get further away, what does this mean? (2)

Answer 24

shared electrons further from halogen nucleus + increases shielding by more inner shells of electrons

Question 25

Which factors: shared electrons getting further from halogen nucleus + increased shielding OR increasing nuclear charge is more important?

Answer 25

shared electrons getting further from halogen nucleus + increased shielding

Question 26

As the shared electrons getting further from the halogen nucleus + increased shielding are the more important factors, what does this mean? (hint-electronegativity)

Answer 26

electronegativity decreases going down group

Question 27

Why does melting and boiling point increases going down the group?

Answer 27

as larger atoms have more electrons

Question 28

As larger atoms have more electrons how does this affect VDW forces?

Answer 28

makes the van der Waals forces between molecules stronger

Question 29

The lower the boiling point the more _____ the element?

Answer 29

the more volatile the element