Unit 1.1 Bridging booklet and Formulae & equations

Question 1

Tell me about elements and I s’pose general basic knowledge w/ periodic table

Answer 1

Element = contains only one type of atom

Consists of:
Proton = +1
Neutron = 0
Electron = -1

Electrons found in shells and has negligible mass

Atomic number = n° of protons
Relative atomic mass = n° protons + neutrons in nucleus

Question 2

Tell me general knowledge of valency

Answer 2

Positive ions = cations
Negative ions = anions

If you were to try find the valency of an element:
Positive = Groups 1-3 = +1, +2, +3, +4 (lead)

Negative = Groups 7-4 (reverso) = -1, -2, -3, -4

Elements u can’t rlly determine by periodic table:
- This is due to the fact that some ions have varying valencies
Positive
+1 = silver, copper(I), ammonium, mercury
+2 = copper (II), zinc, manganese(II), iron(II)
+3 = iron(III), chromium(III)
+4 = manganese(IV)
+5 = vanadium(V)
+6 = chromium(VI)

Negative
Take it or leave it :v

Question 3

Tell me general knowledge of chemical formulae

Answer 3

All compounds are neutral, therefore each element charge gotta equal 0

e.g. MgO, magnesium = +2, oxygen = -2

Question 4

Actually, instead of stating general knowledge, perhaps I can just say what to expect right?

Answer 4

Sure.

U already stated the stuff above so no worries
What’s next:
1. Writing simple compounds
- Pretty self explanatory

2. Half equations
   - This will come in unit 1.2, basically writing down their first ionisation energy. It also can be their beta decay too (some reason physics just had to be here huh?)
   e.g. m -> m^+ + e^- (for a metal)
   X + e^- -> X^- (for a non-metal)
3. Balancing
   - I’ll technically state this later one as yano, formulae & equations
4. Moles
   - It’s like the term to denote the mass of an element using avagadro’s constant
   - Or if u don’t want the definition, the number infront in any chemical formula
   - Considering that too, times that by avagadro’s cosntant to get the actual no° of atoms sooo ye

5. Ur typical formulas
- Pretty important, u aren’t actually given formulas unfortunately so u’ll sadly have to know these
- There is still another booklet dedicated to this anyway but I’ll tell u one that u should obviously know:
Liquids
c = n/v (c = concentration mol/dm^3, n = mols, v = volume dm^3)
Solids
n = mass/mr (n = mols, mass = mass, mr = relative atomic mass)
Gas
n = v/Vm (n = mols, v = volume, Vm = molar volume)

In addition, there’s unit conversions u needa know e.g. dm^3. But ig it’s given in the data booklet :P

6. Electron distribution in an atom
   - I think this is ur s/p/d orbitals
   - Box notations n shi
   - Tho there’s also from origin: dot & cross diagrams
   - But i think the main thing is above that which’ll be in 1.2
7. Covalent & ionic bonding
   - Elements reacting to each other by gaining/losing electrons = ionic bonding
   - Elements sharing electrons = covalent bonding
   - Pretty much dot and cross diagrams for these too, should know how this works based off knowing the difference
8. Advanced electronic configuration
   - I s’pose in-depth of #6
   - S-orbitals = circle
   - Px-orbitals = infinity
   - Py-orbitals = peanut
   - Pz-orbitals = diagonal hourglass
   In addition, the levels too:
   1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, etc.
   s = 2 electrons, p = 6 electrons, d = 10 electrons
   - remember this the box notation, but ofc i’ll go in more detail later
9. Ionisation energy
   - Explaining the trend of ionisation energy, trust me I used to be a dapper at this
   - But ye, briefly:
10. Size of positive nuclear charge
11. Shielding effect based on n° of shells
12. Atomic radii decrease across a period

That’s it for now, but ye there’s more to come O_o

Question 5

Tell me the rules of oxidation number

Answer 5

1. Oxidation number of uncombined elements is zero
2. Sum of the oxidation number in a compound is zero
   - So the positives and negatives, gotta equal zero all together
3. In ionic compound, sum equals overall charge
   - NO3 ig, that’s ionic, and it’s -1
4. In compounds the oxidation numbers of group 1 metals is +1 and group 2 metals +2
   - Ye ik that chat
5. Oxidation number of oxygen in compounds is -2 except with fluorine, peroxides and super oxides
   - SO2, oxygen is now -1
   - H2O2, oxygen is also now -1
6. Oxidation number of hydrogen is +1 in compounds except in metal hydrides
   - HCl, hydrogen is +1
   - NaH, hydrogen is -1
7. In chemical species with atoms of more than one element, the most electronegative element is [give?] the negative oxidation number
   - CCl4
   - Carbon = +4
   - Each chlorine = -1

Question 6

Tell me the ways of balancing?

Answer 6

• Simple dimple buddy
• Look at their valency based on table
  -Voila

Question 7

Tell me the way of writing ionic equations

Answer 7

• Seems complex, but I’m not gonna even through this
• I’m just gonna use my basic knowledge so fuck that