MOUDLE 2 FOUNDATIONS IN CHEM {MR WEDGE}

what is the mathematical formula to know how many electrons are in each shell and what does it tell you

2n^2 where n is the number of shell

how many electrons are in the first shell

2

how many electrons are in the second shell

8

how many electrons are in the third shell

18

how many electrons are in the 4th shell

32

how many electrons are in the fifth shell

50

what are subshells

smaller shells inside a shell

what are the type of subshells

s,p,d,f

what is the first subshell

s subshell

what is the second subshell

p subshell

what is the 3rd subshell

d subshell

what is the 4th subshell

f subshell

what shape is the s orbital

sphere

what shape is the p orbital

dumbell

what is an orbital

an area of space around a nucleus that only contains two electrons with opposite spins

how many orbitals are in the s subshell

1

how many orbitals are in the p subshell

3

How many orbitals are in the d subshell?

5

how many orbits are in the f subshell

7

how many electrons are allowed to be in the s subshell

2

how many electrons are allowed to be in the p subshell

6

how many electrons are allowed to be in the d subshell

10

how many electrons are allowed to be in the f subshell

14

what is the idea behind knowing how many orbits are in a, p, d and f subshells

they are the first 4 odd numbers

what is the idea behind knowing how many electrons you can have max in each orbital

multiply the number of orbits in the subshell you need to find by 2

what is the pattern of the filling order of the electron thingy

1s, 2s, 2p, 3s,3p,4s, 3d,4p,5s,4d,5p……

what is something you have to remember in the electronic filling thing

it goes normally i.e 1s,2s,2p,3s,3p then after 3p the order changes so d and p swap positions and s stays the same so after 3p it looks like: 3p, 4s, 3d, 4p,5s,4d,5p….

Aufbau principle what does it look like and list it

which two elements do not follow the normal pattern of electronic configuration

cooper and chromium

what are the noble gas configuration of the two elements that do not follow the normal pattern of electronic configuration

cr: [AR] 4s1 3d5 cu: [AR] 4s1 3d10

when doing electronic configuration what is the rule for ions

electrons only gain or loose from the outermost shell. REMEBERRRRR

when doing orbital box diagrams what is one thing u must remember

you put one electron in each one until you fill the orbitals then start filling again. DO NOT PUT TWO AT A TIME

what is electronegativity

the ability of an ATOM to attract electrons in a covalent bond. NOT AN ELECTRON

why are H2O molecules polar

because DIPOLES do not cancel out

the periodic table is divided into blocks what are they and what blocks are each group contained at

1, 2 and helium = s block 3 to 12= d block 13-17-= p block the ones at the bottom= f block

why is electronic configuration an example of a periodic trend

because elements in the same group all have the same number of electrons in the outermost shell AND this pattern repeats as you move from one period to the next.

what is a d block element

this is just an elements where its highest energy electron is found at a d subshells. THIS IS THE SAME FOR OTHER ELEMENTS

What is the difference between a d-block element and a transition element

Transition: Forms at least one stable ion with a partially filled d-subshell

Why are Scandium and Zinc d-block elements but not transition elements? (Include ion configurations)

They are d-block because their highest energy electrons are in the 3d subshell. However: Scandium ((\text{Sc}^{3+})): ([Ar] 3d^0). Its only stable ion has an empty d-subshell. Zinc ((\text{Zn}^{2+})): ([Ar] 3d^{10}). Its only stable ion has a completely full d-subshell. (Neither forms an ion with a partially filled d-subshell!)

what is the idea behind the VESPA theory

electron pairs around the central atom is negatively charged so they repel each other and arrange themselves as far as possible which determines the shape of the molecules

what do we use when drawing 3 dimensional shapes on a flat piece of paper

wedges

what does a solid line represent

a bond that lines flat on the paper

what does a solid wedge represent

a bond that goes out of a plane

what does a dotted/broken wedge reperesent

a bond going to the back

what is an electron pair

just two electrons

what are the two types of electron pairs

Bonding pairs and lone pairs

what is a bonding pair

2 electrons used to make a bond

what is a lone pair

pairs of electrons that are not bonded

what shape would a molecule with 2 bonds form

linear

what shape would a molecule with 3 bonds form

trigonal planar

what shape would 4 bonded pairs form

tetrahedaral

what shape would a molecule with 5 bonds form

triagonal bipyramidial

what shape would a bond with six bonded pairs form if there are no lone pairs

octahedral

what angle would a molecule that has a linear shape have (that have no lone pair )

180

what angle would a molecule with a triangular planar have (that has no lone pairs )

120

what angle with a molecule with a tetrhedral have (that has no lone pair)

109.5

what angle with a molecule with a triagonal bipyramidal shape have

90 and 120

what angle with a molecule with a octahedral have

90

a molecule with 2 lone pair and two bonded pairs would form what shape

bent

a shape with 3 bonded pair and 1 lone pair is called what

pyramidal

with lone pairs you only count em to find yor original starting bond angle as bond angle is lone plus bonding. when dont u count em

when determining/drawing to shape of the molecule

what is the formula to find out the angle of a molecule shape

360/ number of pairs(both lone and bonding)

after what number of electron pair does the rule for finding angles stop working

once u reach the 4th bond

when does the general angle i.e 180, 120 and 109.5 stop being true

when u have lone pairs

how do u calculate the angle of the molecules when u have lone pairs

for every lone pair u take away 2.5 from the general angle of the number of that particular bond

why do lone pairs reduce the shape angle

lone pairs repel other electron pairs more strongly than bonding pairs do causing bonding pairs to be pushed closer together which reduces bond angles

why do lone pairs repel more strongly

they are attracted to only one nucleus so thier density is concntrated to the central atom

when u are given a molecule that is ionic what do u do if asked for the VESPA thing

you solve it as normal as they have alr gained or lost the electrons it needed to loose or gain

what is the difference between the shape of a molecule and electron arrangement

shape of a molecule does not include the lone pairs while electron arrangement does

what is intermolecular forces

this is the bonding between two molecules

what are the types of intermolecular forces

1. induced dipole-dipole interaction( london forces)
2. permanent dipole-dipole interaction
3. hydrogen bonding

what is the order of strength for these intermolecular forces strongest to weakest

hydrogen bonding, permanent dipole-dipole interaction, induced dipole-dipole interaction( london forces)

explain london forces

The random movement of electrons creates a temporary dipole, which induces a dipole in a neighboring molecule, causing an attraction."

explain permanent dipole-dipole interaction

An attraction forms between the slightly positive end of one polar molecule and the slightly negative end of a neighboring polar molecule.

explain hydrogen bonding

An attraction forms between the lone pair of electrons on a highly electronegative atom of one molecule and the slightly positive hydrogen atom of a neighboring molecule

with what elements do hydrogen bonding occur

between a lone pair on either a nitrogen flourine or oxygen atom and a slightly positive hydrogen

why is more energy required to break bonds in a large molecule

large molecules have more electrons, causing a stronger temporary dipole resulting in stronger london forces so more energy is required to overcome the intermolecular forces between molecules

explain why branched isomers have a lower boiling point that straight isomers

in an isomer branches make the structure more compact so the surface area reduces causing fewer points of surface contact between molecules so weaker london forces so less energy needed to overcome them

what are the anomolous property of water

1. it has a high boiling point
2. liquid ice is more dense than ice

why does water have a high boiling point

water is a polar molecule so it bonds to other polar molecules or itself via hydrogen bonds and hydrogen bonds are very strong so more energy is needed to overcome these intermolecular forces

what should you now say instead of "break these bonds "

overcome intermolecular forces

why is liquid water more dense than solid water

in the liquid state, the molecules in water have thermal energy so they are able to move around, forming and breaking HYDROGEN bonds with other similar molecules. this cause the molecules to be tightly packed together making them very dense

why is solid water less dense than liquid water

when water freezes the molecules lose thier kinetic energy so they become fixed and stable. this allows the molecules to form four hydrogen bonds with neighbouring molecules causing them to spread out. INTO AN OPEN LATTICE

the rule "like dissolve like" what does it mean

it means that polar molecules dissolve in polar molecules while non polar molecules dissolve in other nonpolar molecules

why do two non polar molecules dissolve with each other

cause they can form london forces

why do two polar molecules dissolve with each other

they form permanent dipole dipole interaction or hydrogen bonds

when would two polar molecules form a hydrogen bond

only is they contain N,O or F

why does ice have a lower density than water (1 mark)

because its hydrogen bonds hold the molecules apart