3.4- ELECTRONEGATIVITY- BOND POLARITY IN COVALENT BONDS

Question 1

What are the forces that hold atoms together all about?

Answer 1

attraction of positive charges to negative charges

Question 2

What happens in ionic bonding? (transfer)

Answer 2

complete transfer of electrons from one atom to another

Question 3

Are the electrons always evenly spread out in a covalent bond?

Answer 3

no

Question 4

When are the electrons not evenly spread out in a covalent bond?

Answer 4

when one of the atoms is better at attracting electrons than the other one

Question 5

What is the atom that is better at attracting the electrons than the other atom in a covalent bond said to be?

Answer 5

more electronegative

Question 6

What is the definition of electronegativity?

Answer 6

power of an atom to attract the electron density in a covalent bond towards itself

Question 7

What is the term electron density often used to describe?

Answer 7

way the negative charge is distributed in a molecule

Question 8

What is used as a measure of electronegativity?

Answer 8

Pauling scale

Question 9

What does the Pauling scale run from?

Answer 9

0 to 4

Question 10

What does a greater number on the Pauling scale mean?

Answer 10

more electronegative the atom

Question 11

What number does the noble gases have on the Pauling scale?

Answer 11

no number

Question 12

Why do the noble gases not have a number on the Pauling scale?

Answer 12

generally they do not form covalent bonds

Question 13

What does electronegativity depend on? (3)

Answer 13

nuclear charge

distance between nucleus and outer shell electrons

shielding of nuclear charge by electrons in inner shells

Question 14

What happens to electronegativity as the size of the atom decreases?

Answer 14

smaller the atom, greater the electronegativity

Question 15

Why does electronegativity increase as the size of the atom is smaller?

Answer 15

closer the nucleus is to the shared outer main level electrons

Question 16

What happens to electronegativity the larger the nuclear charge?

Answer 16

greater the electronegativity

Question 17

How does electronegativity change going up a group?

Answer 17

increases

Question 18

Why does electronegativity increase going up a group?

Answer 18

less shielding by electrons in inner shells

Question 19

How does electronegativity change going across a period?

Answer 19

increases

Question 20

Why does electronegativity increase going across a group? (3)

Answer 20

nuclear charge increases

number of inner main levels remain the same

atoms become smaller

Question 21

Where are the more electronegative atoms found on the periodic table?

Answer 21

top right-hand corner (ignoring noble gases)

Question 22

What are the most electronegative atoms? (4)

Answer 22

fluorine

oxygen

nitrogen

chlorine

Question 23

What is polarity about?

Answer 23

unequal sharing of electrons between atoms bonded together covalently

Question 24

What is polarity the property of?

Answer 24

property of the bond

Question 25

How must the electrons in a bond between atoms that are the same be shared?

Answer 25

must be shared equally between the atoms

Question 26

Why must the electron be shared equally in a bond between atoms that are the same?

Answer 26

both atoms have exactly the same electronegativity

Question 27

What is the polarity of the bond between two of the same atoms like?

Answer 27

non-polar

Question 28

How will the electrons be shared in a covalent bond between two atoms of different electronegativity?

Answer 28

electrons would not be shared equally between the atoms

Question 29

How is the electron cloud described to be when the atoms have different electronegativities in the bond?

Answer 29

distorted

Question 30

What relative charge would the atom with a higher electronegativity have?

Answer 30

relatively negative

Question 31

What relative charge would the atom with a lower electronegativity have?

Answer 31

relatively positive

Question 32

What is the polarity of the bond between atoms who have different electronegativities?

Answer 32

polar

Question 33

What is the polarity of the bond like the greater the difference in electronegativity?

Answer 33

the more polar the covalent bond

Question 34

How can you say a covalent bond has some ionic characters?

Answer 34

it may be going some way towards the separation of the atoms into charged ions

Question 35

Is it possible to have ionic bonds with covalent characters?

Answer 35

yes