Topic 3/13

Question 1

What do you think of when it asks for most reactive?

Answer 1

Bonds and their strengths

Question 2

Which transition element ion is colourless? why?

Answer 2

Sc3+

Electron configuration has unpiared d electrons so considered transition metal but in ionic form as 3+ there is no unpaired so not splitting so colourless

Question 3

What is trend for ionic radius across a period and down a group?

Answer 3

Decrease across period but then huge jump from cations to anions because nuclear charge increases

Cation smaller than parent and anion larger
Largest cation charge is the smallest and largest anion charge is the biggest

Question 4

Outline oxide trends

Answer 4

Basic (metals) to acidic (non metals) and Aluminim oxide is amphoteric but does not react with water

Question 5

Equations for Na2O, MgO and P4O10 with water

Answer 5

Na2O + H20 = 2NaOH
MgO + H2O = Mg(OH)2
P4O10 + 6H2O = 4H3PO4

Question 6

Trends in atomic radius

Answer 6

Decrease across period (pos cahrge so higher valence pull)

Increases down group more shielding effect

Question 7

Trends in ionic radius

Answer 7

Decrease across period for cations, jump and then decrease for ions (as nuclear charge increases ionic radius decreases)

Increases down group, more shielding effect

Question 8

Trends in first ionization energy

Answer 8

Increaes across period (number of ptoons)
Decreases down group

Question 9

Exceptions to trends in first ionization energy

Answer 9

Decrease from Beryllium to Boron and Magnesium to Aluminum (less energy to remove p orbital than s)

Decrease from Nitrogen to Oxygen and Phosphorus to Silver (less energy to remove doubly occupied orbital than half filled

Question 10

Trends in electronegativity

Answer 10

Attract electrons to itself (flourine highest)
Increase across period
Decrease down group

Question 11

Trends in electron affinity

Answer 11

1 lol e added to 1 mol gaseous
Increase across period (group 18 can accommodate electron easily)
Decrease down group

Question 12

What does it mean if species is lower in spectrochemical series?

Answer 12

Less splitting and energy and wavelength of light absorbed increases

Question 13

How to figure out which group an element is in based on ionization data?

Answer 13

Group 13, big jump between 3-4

Question 14

Trend for melting and boiling points for group 1 and 17

Answer 14

MELTING
Decrease down group 1, increase down group 17

BOILING
Increase down group 1
Decrease down group 17

MD doctor
BI boiling

Question 15

Explain why Si has a smaller atomic radius than Al (2)

Answer 15

• Higher nuclear charge so stronger pull on outer electrons
• Same number of shells

Question 16

Explain why the first ionization energy of sulfur is lower than that of phosphorus (2)

Answer 16

P has three unpaired electrons in the 3p sublevel while S has one full 3p orbital and two unfilled 3p orbitals

There is repulsion between electrons in the full 3p orbital in sulfur making it easier to remove for more stable sub level

Question 17

Trend for melting point across period?

Answer 17

Alwaysrelate to metallic bonding. Smaller atomic radius as you go across cations causes stronger metallic bonidng but then you have molecular covalent and not much metallic bonding, slight decrease

Question 18

Predict how first ionization energy of 15N compares with that of 14N

Answer 18

Same because same nuclear nuclear charge and nuetrons do not affect ionization energy

Question 19

Why do transition metals form coloured compounds?

Answer 19

They have partially filled d orbitals. Ligands cause d orbitals to split and light is absorbed as electrons are prompted to higher energy levels. Energy gap corresponds to specific wavelength that gets absorbed and complementary colour is transmitted and observed

Question 20

Which group of elements in the periodic table most likely to undergo sublimation?

Answer 20

Group 18 bc smallest difference between melting and boiling points and weakest IMF

Question 21

Describe paramagnetism

Answer 21

Aligns with magnetic field, attracted to external magnetic filed, mention unpaired electrons, has magnetic moment

Question 22

Why is first ionization energy of sulfur lower than phosphorus

Answer 22

Phosphour does not have paired electrons

Less energy to remove doubly occupied orbital than half filled bc electrons in doubly occupied repel each other

Question 23

Why is first ionization of boron lower than berillym

Answer 23

takes less energy to remove from p orbital becuase father away from nucleus

Question 24

What can be deduced from the period of an element?

Answer 24

Highest occupied energy level and number of sub levels in outer shell

Question 25

Why does the melting point of elements decrease down group1?

Answer 25

Radius of metal ion increases

Question 26

Ferromagnetic

Answer 26

Unapired e align with external mag field and pesist, object magnetism

iron, cobal, nickle

Question 27

Diamagnestim,

Answer 27

only paired electrons, cancel magnetic effect like zinc, non magnetic