OCR A 3.1.1 Periodicity REVISION

[@alishbashaikh410]

seriously i cannot stress enough, your videos are extremely helpful and I really appreciate the time and effort you put into them. Thank you so much!!

[@taha4359]

yw

[@imma_eatjin]

u don’t understand i would honestly do anything for this channel right here i literally will sacrifice my life if it meant saving this channel THANK YOU SO MUCH

[@zayd4684]

best tutor for OCR honestly

[@ellenbloomfield8790]

How do you work out when to say what forces and bonds are being used and how to work out if something is giant covalent/ionic or simple molecular etc... I understand them all individually but I’m struggling to work out when to apply what

[@alishbashaikh410]

at college, we labelled out the periodic table and in that group 4 was labelled as giant covalent, 5,6 and 7 as simple covalent, and the rest as metallic. Hopefully this helps you!

[@rali1243]

Any metal with non metal is ionic. Giant covalent compounds, just memorise Simple molecular is any covalent compounds between non metals only that are not one of the giantncovalent compounds Metallic compounds are every metals bonded together

[@shumailaiftikhar7287]

This might be a silly question but how can you tell that silicon has a giant covalent structure?

[@AlleryChemistry]

Just have to remember it. Carbon is the same but comes in different forms - graphite, diamond and nanotubes!

[@gelato4155]

Do your videos cover all of OCR A spec or is it just a few videos

[@topinfo6446]

At 17:10 you said in the yellow box that grapheme is only 1 cell thick

[@mayarokii]

I haven't watched that part of the vid yet but he probably meant one atom thick

[@p.p6343]

Hi, why does atomic radius decrease across a period? The number of sub shells increases across a period so wouldn't this cause the radius to increase? Thanks

[@reubenconstantine2685]

p. P really confused me for a while but it’s just that, proton number increases therefore electrons pulled tighter to nucleus. This effect is only overridden at the start of a new shell (not sub shell)

[@rali1243]

Atomic radius decreases as there are more protons so nuclear attraction on outer electron shell increases pulling it closer to it so overall size of atom slightly decreases

[@mayarokii]

Sub-shells changes but doesn't change the number of actual shells - the number of shells stays the same. The number of protons in the nucleus increases, so the positive nuclear charge increases - this pulls electrons in much stronger as it strengths electrostatic attraction, so the overall atom has a smaller radius.

[@Inferno-ob9td]

Isn’t shielding basically the same as atomic size?

[@arati1097]

Inferno ❶ Hi this might be late but shielding refers to the number of electrons and electron repulsion while atomic size refers to the number of shells and the distance between the outer electrons and the nuclei

[@alishbashaikh410]

@@arati1097 sorry Alaska , I just had to correct you, you have got the two wrong way around!

[@alshohb]

HI I know it has been a whole year since the video was uploaded but got question u say simple molecular bonds does not conduct electricity but how come water is an example of simple molecular bonds and can conduct electricity

[@alishbashaikh410]

water is polar thats why

[@jakebrown5967]

Water doesn't conduct electricity (pure water), it is the ions dissolved in water that conduct it. Look up people putting a phone in deionised water or something like that.

[@yujirohanma203]

@@alishbashaikh410 no that's not the reason, it's because of what's dissolved in the water (ions and impurities)

[@sea5205]

Ur channel is really helpful, thanks a alot!

[@Fatima-k]

How do the delocalised electrons in graphene strenghthen the covalent bonds between the carbon atoms?

[@alishanamakula]

Shielding 6:50

[@aaminahsarfaraz4304]

Thank you for this video!

[@AlleryChemistry]

Glad it was helpful!

[@Nilo-g6n]

When are you going to make the ocr A2 videos?

[@nimo2714]

Can I ask what you got in your a levels

[@sea5205]

So helpful, thanks a lot!

[@Ilya_012]

Thank you❤

[@AlleryChemistry]

No problem

[@Ilya_012]

@@AlleryChemistry 😊🥰

[@markixx3375]

Great video bud

[@Joe-ip7je]

Hi! What's the difference between nuclear charge and effective nuclear charge, does it matter if I just use nuclear charge in the exam?

[@lucasl4644]

electrons shield the charge so if there are more electrons then the is less effective nuclear charge

[@gjeraldh2989]

11 hours left

[@bennieakparobi3221]

what would i do without you lol?