Foundations in chemistry

Question 1

What is the real active mass of an electron proton and neutron

Answer 1

Proton is 1
Neutron is 1
Electron is 1/1836

Question 2

What is an isotope

Answer 2

Atoms of the same element with the same number of protons but a different number of neutrons

Question 3

What is relative isotopic mass

Answer 3

Mass of an atom of an isotope compared with 1/12th mass of carbon 12

Question 4

What is relative atomic mass

Answer 4

Weighted mean mass of an atom of an element compared with 1/12th mass of carbon 12

Question 5

How many electrons are on each shell

Answer 5

1 has 2 electrons
2 has 8 electrons
3 has 18 electrons
4 has 32 electrons

Question 6

What is a orbital

Answer 6

A region of space around the
Nucleus that can hold two electrons with paired spins

Question 7

What orbitals do each energy levels have

Answer 7

1st has only s
2nd has s and p
3rd has s , p and d
4th has s , p , d and f

Question 8

How many orbitals do each sub shell have

Answer 8

S has 1
P has 3
D has 5
F has 7

Question 9

Why do electrons in the same orbital get drawn as oppositely facing arrows

Answer 9

The negative electrons repel each other and it also indicated the electrons spin

Question 10

What is the electron configuration of carbon

Answer 10

1s2 2s2 2p2

Question 11

how to write short hand electron configuration

Answer 11

replacing orbitals with the most recent preceding noble gas’s known electron configuration

Question 12

what is the shorthand configuration of chlorine

Answer 12

[Ne]3s²3p5

Question 13

what are the noble gas facts

Answer 13

full valence electron shells
monoatomic non metal gases at room temp
very stable
high ionising energies
do not combust
low bp

Question 14

what is ionic bonding

Answer 14

electrostatic attraction between oppositely charged ions

Question 15

what happens to electrons in ionic bonding

Answer 15

they are transferred

Question 16

what is a covalent bond

Answer 16

shared pair of electrons

Question 17

What is a dative covalent bond

Answer 17

when a shared pair of electrons that have been donated by only of the bonded atoms for example NH4

Question 18

What groups can break the octet rule

Answer 18

5-7

Question 19

In double and triple covalent bonds all atoms have the structure of the…

Answer 19

Nearest noble gas

Question 19

How is expanding the octet possible

Answer 19

In the. 3rd shell when a d sub shell becomes available

Question 20

How do dative covalent bonds usually occur

Answer 20

When a compound reacts with a H+ ion

Question 21

What is the name and bond angle of a covalent molecule with 2 electron pairs

Answer 21

Linear
180

Question 22

What is electron repulsion theory

Answer 22

The shape of a molecule is determined by the number of electron pairs as electrons repel each other

Question 23

What is the name and bond angle of a molecule with 3 electron pairs

Answer 23

Triagonal planar
120

Question 24

What is the name and bond angle of a molecule with 4 electron pairs

Answer 24

Tetrahedral 109.5

Question 25

What is the name and bond angle of a molecule with 5 electron pairs

Answer 25

Trigonal bipyramidal 120/90

Question 26

What is the name and bond angle of a molecule with 6 electron pairs

Answer 26

Octaheadral 90

Question 27

What is the name and bond angle of a molecule with 1 lone pair

Answer 27

Pyramidal 107

Question 28

What is the name and bond angle of of a molecule with 2 lone pairsb

Answer 28

Non linear 104.5

Question 29

what is electronegativity

Answer 29

A measure of the ability of an atom to attract a bonding pair of electrons in a covalent bond

Question 30

What are examples of very electronegative elements

Answer 30

oxygen, florine, chlorine, nitrogen etc

Question 31

what are factors affecting electronegativity

Answer 31

atomic charge distance from the nucleus electron shielding

Question 32

what is a HCl bond known as

Answer 32

polar covalent bond

Question 33

what must a molecule be for it to be polar

Answer 33

asymmetrical

Question 34

what does a polar molecule form

Answer 34

a dipole

Question 35

why are symmetrical molecules non polar

Answer 35

the dipoles cancel each other

Question 36

do lone pairs cause symmetrical or asymmetrical molecules

Answer 36

asymmetrical

Question 37

what is an intermolecular force

Answer 37

an attractive force between neighbouring molecules

Question 38

what are the 3 types of intermolecular forces

Answer 38

-permanent dipole-dipole interactions -london forces -hydrogen bonds

Question 39

what is the strongest and weakest intermolecular force

Answer 39

hydrogen is strongest london in weakest

Question 40

explain a permanent dipole force

Answer 40

-Its a weak attractive force between permanent dipoles in neighbouring polar molecules -The permanent dipole of one molecule attracts the permanent dipole of another

Question 41

explain london forces

Answer 41

-They act between all molecules, whether they are polar or non polar -Electrons might find themselves towards one side of the molecule because they are mobile, forming a temporary dipole -This creates induced dipoles which are attracted to the temporary dipoles

Question 42

explain hydrogen bonding

Answer 42

-Electrostatic forces of attraction between a proton deduced of electrons attached to an electronegative atom and the lone pair of another electronegative atom

Question 43

why is ice less dense as a solid

Answer 43

the hydrogen bonds hold the H2O molecules in an open lattice shape as a solid, bit as they melt the molecules move closer together

Question 44

what elements does hydrogen bonding happen to with hydrogen

Answer 44

Nitrogen, Oxygen and Florine

Question 45

What is metallic bonding

Answer 45

The electrostatic attraction between positive metal ions and delocalised electrons

Question 46

What are the properties of giant metallic lattices

Answer 46

High mp and bp Good electrical conductors Malleable and ductile

Question 47

What do giant metallic lattices have high melting points and boiling points

Answer 47

Strong electrostatic attraction between positive metal ion and delocalised electrons which require a lot of energy to overcome

Question 48

Why are giant metallic lattices good electrical conductors

Answer 48

Delocalised electrons are free to move and carry a charge

Question 49

Why are giant metallic lattices malleable and ductile

Answer 49

The ions are able to move past each other into new positions whiteout breaking metallic bonds

Question 50

What is an alloy

Answer 50

A mixture of metals

Question 51

what is an ionic lattice

Answer 51

regular repeating pattern of oppositely charged ions

Question 52

what are the properties of ionic compounds

Answer 52

-Conductors when molten -High mp and bp -Soluble in polar solvents

Question 53

explain why ionic lattices are conductors when molten

Answer 53

ions are free to move through the structure

Question 54

explain why ionic lattices have high melting and boiling points

Answer 54

electrostatic attraction between oppositely charged ions is so strong large amounts of energy are needed to overcome

Question 55

what can increase electrostatic attraction in ionic compounds/lattices

Answer 55

higher ion charge

Question 56

explain why ionic lattices are soluble in polar solvents

Answer 56

polar molecules break down the lattice by surrounding each ion to form a lattice; positive ion in solvent to negative ion in lattice, and negative ion in solvent to positive ion in lattice

Question 57

What are properties of simple molecular substances

Answer 57

-weak and soft when solid due to intermolecular forces -don’t conduct electricity as not charged -soluble in non polar solvents because London forces form between the solvent and molecule

Question 58

what are the differences between graphite and diamond

Answer 58

graphite can conduct electricity but diamond cannot