Chem maters & materials p1

Question 1

orbital

Answer 1

a region of space around the nucleus where the electrons are most likely to be found

Question 2

valence electrons

Answer 2

electrons in the outermost energy levels of an atom

Question 3

chemical bond

Answer 3

an electrostatic force holding atoms together in a molecule or crystal

Question 4

bond energy

Answer 4

the energy required to break a particular bond in a compound

Question 5

electrostatic force

Answer 5

force that charged particles exert on each other

Question 6

covalent bond

Answer 6

a chemical bond that forms when atoms share their outermost electrons

Question 7

octet rule

Answer 7

atoms tend to combine in such a way that they each have 8 electrons outer energy level, giving them the same electron configuration s a noble gass

Question 8

coordinate band (dative covalent bond)

Answer 8

covalent bond in which both electrons come from the same atom

Question 9

lone pair

Answer 9

valence electron pair that does not bond or share with other atoms

Question 10

electronegativity (EN)

Answer 10

a measure of how strong an atom attracts the shared pair of electrons in chemical bond

Question 11

non-polar bond

Answer 11

a covalent bond in which both atoms attract the bonding electrons equally

Question 12

polar bond

Answer 12

a covalent bond in which electrons are pulled closer to the atom with the higher electronegativity

Question 13

Bond length

Answer 13

the distance between the nuclei of covalently bonded atoms

Question 14

Bond energy

Answer 14

the amount of energy that is required to break one mole of a particular covalent bond in the gaseous state

Question 15

Bond order

Answer 15

the number of bonds that exist between two atoms

Question 16

interatomic force

Answer 16

an electrostatic force of attraction between atoms due to the sharing or transfer of electrons

Question 17

intermolecular force

Answer 17

the attraction between molecules

Question 18

Hydrogen bonding

Answer 18

a force of attraction between hydrogen atom bonded to oxygen, nitrogen, fluorine in a molecule and the lone pair of electrons on oxygen, nitrogen or fluorine atom bonded to hydrogen in an adjacent molecule.

Question 19

vapour pressure

Answer 19

the pressure of gas molecules of a substance in contact with its liquid or solid form

Question 20

boiling point (b.p.)

Answer 20

the temperature at which the vapour pressure of the liquid equals the external atmospheric pressure surrounding the liquid