Electrons bonding and structure Module 2

Question 1

Order of filling up of subshells?

Answer 1

1s^2
2s^2
2p^6
3s^2
3p^6
4s^2
3d^10 (writen before 4s)
4p^6
4d^10
4f^14

Question 2

Label the notation for electronic configuration?

Answer 2

number in front is energy level
letter in middle is the subshell
number it’s to the power to is the number of electrons

Question 3

Features of an orbital?

Answer 3

It’s a bit of space that an electron moves in
Can hold up to 2 electrons with opposite spin (spin-pairing)
Orbitals within the same sub-shell have the same energy

Question 4

What shape are s orbitals?

Answer 4

Spherical

Question 5

What shape are P orbitals?

Answer 5

Dumbbell

Question 6

How do you fill up orbitals?

Answer 6

Put an arrow in each box facing one direction, and once every box is filled in subshell can start adding arrow in opposite direction to the orbitals
All orbitals must be filled before going to next subshell

Must take into account how many electron there actually is in ions

Question 7

What is an ionic bond?

Answer 7

The electrostatic attraction between 2 oppositely charged ions

Question 8

How to draw a dot and cross diagram?

Answer 8

Draw every chemical with only it’s outer ring of electrons
Draw arrows from element which is donating the electrons to the other atom(s)
Redraw both of them with the positive ion having empty outer shell and a bracket with it’s charge, and negative ion with full outer shell (including different shaped electrons from other atom)
Remember number in front if there’s more than 1

Question 9

Describe Sodium chlorides giant ionic lattice?

Answer 9

Na+, and Cl- ions packed together alternately in a regular structure called a lattice
“giant” as it’s a repeating structure
Each ion is electrostatically attracted in all directions to ions of the opposite charge

Question 10

Why do ionic compounds conduct electricity when molten or dissolved but not when solid?

Answer 10

The ions in a liquid are mobile (and they can carry charge)

In a solid they aren’t mobile

Question 11

Why do ionic compounds have high boiling and melting points?

Answer 11

Giant ionic lattices held together by strong electrostatic forces which require a lot of energy to break

Question 12

Why do ionic compounds tend to dissolve in water?

Answer 12

Water molecules are polar, so attracted to the charged ions

They pull the ions away from the lattice causing it to dissolve

Question 13

Covalent bond definition?

Answer 13

Strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 14

What’s the average bond enthalpy?

Answer 14

Amount of energy required to break a covalent bond

Question 15

What’s a dative covalent bond?

Answer 15

Where both electrons come from one atom
Eg when ammonia has a H+ ion added to it to for a ammonium + ion, both electrons come from the Nitrogen
When drawing dot and cross arrow goes towards H+, instead of just a normal line

Question 16

What determines molecular shape?

Answer 16

The electron pairs around the central atom

Question 17

Order of the size of angles produced by electron pairs?

Answer 17

Lone pair- Lone pair is biggest
Lone pair-Bonded pair second
Bonded pair- Bonded pair smallest

Question 18

What do you do if there is a double bond when predicting the shape of a molecule?

Answer 18

Treat them the same as single bonds

Question 19

What does 2 electron pairs around the central atom produce?

Answer 19

Linear molecule

180 degrees

Question 20

3 bonded pairs around the central atom?

Answer 20

Trigonal planar

120 degrees

Question 21

4 bonded pairs around central atom?

Answer 21

Tetraherdral (Tripod shaped, use lined wedge and filled in wedge)
109.5 degrees

Question 22

3 bonded pairs and one lone pair around central atom?

Answer 22

trigonal pyramidal, (lone pair at top, everything splits off evenly from it downwards, use lined wedge, and filled in wedge)
107 degrees

Question 23

2 bonded pairs and 2 lone pairs around central atom?

Answer 23

nonlinear shape (V shaped)
104.5 degrees

Question 24

5 bonded pairs around central atom?

Answer 24

Trigonal bipryamidal
Around central atom there is a straight line going through, and perpindicular to this there is a triangle of atoms (use both wedges in this)
Producing 90 degree angles and 120 degree angles)

Question 25

6 Bonded pairs around central atom?

Answer 25

Octahedral (Use 2 lined wedge, and 2 filled in wedge) | All angles 90 degrees

Question 26

Definition of eletronegativity?

Answer 26

An atom's ability to attract the electron pair in a covalent bond

Question 27

Order of electronegativity of elements from highest to lowest of ones we need to know?

Answer 27

``` Flourine Oxygen Chlorine Nitrogen Carbon Hydrogen (very small difference between carbon and hydrogen means doesn't create polar bonds) ``` Fat Oscar Cums near carrot heavily

Question 28

What happens to covalent bonds when one atom has a much larger electronegativity, and what happens if the atoms are the same?

Answer 28

Electrons pulled to atom with the higher electronegativity making the bond polar ( delta negative and delta positive), Permanent dipole has been formed ( be careful because polar bonds may cancel each other out like in CO2 so no permanent dipole formed) If they are the same then bond isn't polar as attract the electrons equally so no permanent dipole formed

Question 29

Are intermolecular forces very weak or very strong?

Answer 29

Very weak

Question 30

Order of strength of the intermolecular forces from strongest to weakest?

Answer 30

Hydrogen bonding Permanent dipole-dipole interactions Induced dipole-dipole interactions ( London forces)

Question 31

How do induced dipole-dipole forces form?

Answer 31

Found between all atoms and molecules Electrons in charge clouds are moving very quickly so at a particular moment the electrons in an atom are more likely to be more on one side than the other, creating a temporary dipole This dipole can then create another temporary (INDUCED) dipole (as higher electron density repulses the other electrons), which are then attracted to each other Chain affect occurs

Question 32

Which factors increase induced dipole- dipole interactions?

Answer 32

Larger molecules have more electons meaning stronger induced dipole-dipole interactions So does larger exposed surface area has have bigger exposed electron cloud

Question 33

Which molecules can form permanent dipole-dipole interactions?

Answer 33

Polar molecules (Delta positive of one molecule attracted to the delta negative of another)

Question 34

When can hydrogen bonding occur and what does it do to melting and boiling points and other property?

Answer 34

If hydrogen is bonded to fluorine, oxygen or nitrogen Massively increases them Soluble in water

Question 35

Why do simple covalent compouds have low melting and boiling points?

Answer 35

Weak intermolecular forces

Question 36

Why don't simple covalent compounds conduct electricity?

Answer 36

The overall covalent molecules are uncharged so they can't cinduct electricity

Question 37

What happens to the covalent bond when you melt or boil a simple covalent compound?

Answer 37

Nothing, only the intermolecular forces are affected