Electronegativity

Question 1

what is electronegativity

Answer 1

• electronegativity is a measure of the relative tendency of an atom in a covalent bond to attract a bonding pair of atoms
• the ability of an atom to attract the shared pair of electrons in a covalent bond to itself

Question 2

what are the factors affecting electronegativity

Answer 2

• nuclear charge
• atomic radius
• shielding effect

Question 3

how does nuclear charge affect electronegativity

Answer 3

as the nuclear charge of an atom increases across the period, the electronegativity increases

Question 4

how does atomic radius affect electronegativity

Answer 4

as the size of the atom decreases across the period,the electronegativity increases

Question 5

how does the shielding effect affect electronegativity

Answer 5

as the number of shells increases down the group, the shielding effect increases, thus electronegativity increases

Question 6

what is the pauling scale

Answer 6

• a scale for measuring electronegativity values increase across periods values decrease down groups
• fluorine has the highest value

Question 7

what is ionic bonding

Answer 7

ionic bonds tend to be formed between elements whose atoms need to “lose” electrons to gain the nearest noble gas electronic configuration and those which need to gain electrons
-the electrons are transferred from one atom to the other

Question 8

what is metallic bonding

Answer 8

a metallic solid consists of a lattice of positive ions with the outer electrons forming a sea of delocalised electrons. the electrostatic forceof attraction between the delocalised electrons cloud and the metal cations constitute the metallic bond

Question 9

what does the strength of the metallic bond depend on

Answer 9

• if the size of the cation is bigger, the strength of the metallic bond is smaller/weaker
• if the charge of the cation is bigger, the strength of the metallic bond is bigger/stronger

Question 10

how do metal atoms achieve stability in metallic bonding

Answer 10

by off-loading electrons to attain the electronic structure of the nearest noble gas
-these electrons join up to form a mobile cloud which prevents the newly-formed positive ions from flying apart due to repulsion between similar charges

Question 11

what is a covalent bond

Answer 11

• an electrostatic force of attraction between two non-metals to share a pair of electrons
• usually formed if the difference in electronegativity between the atoms are small
• consists of a shared pair of electrons with one electron being supplied by each atom either side of the bond

Question 12

how does difference in electronegativity between atoms in a bond affect the typeof bond

Answer 12

• any difference in electronegativity that is more than 1.5 will result in ionic bonds
• any difference that is less than or equal to 1.5 will result in a covalent bond

Question 13

how are atoms held together in a covalent bond

Answer 13

their nuclei which have an overall positive charge are attractedto the shared electrons

Question 14

what is high charge density

Answer 14

when the power/change is large but the size of the molecule is small