Trends in the Periodic Table

Question 1

Define first ionisation energy

Answer 1

• the energy required to remove one electron from an element

Question 2

Which element has largest first ionisation energy and why?

Answer 2

-neon (noble gas)
- it already has a full outer shell and it is stable, so it will resist giving up an electron

Question 3

explain why there are 8 elements in the second period

Answer 3

• those elements have electrons that fill up the second shell
• each period represents the number of shells an atom has
• 2 in the s subshell, 6 in the p subshell

Question 4

first ionisation energy

Answer 4

the energy required to remove one electron from an element

Question 5

which elements have the largest first ionisation energy?

Answer 5

noble gases e.g neon, as they already have a full outer shell and thus will resist giving up anohter electron

Question 6

effective nuclear charge/core charge

Answer 6

the attractive force felt by valence electrons

Question 7

how to calculate effective nuclear charge?

Answer 7

number of valence electrons

Question 8

why does effective nuclear charge increase across the period

Answer 8

e- are more attracted to the nucleus, hence it is harder to remove from the atom. as first ionisation energy increases, effective nuclear charge also increases

Question 9

state whether na or silicon would have greater first ionisation energy.
(example)

Answer 9

• silicon has greater effective nuclear charge of __, vs sodium __.
• silicon e- are pulled closer to the nucleus and has greater attraction
• therefore, it is harder to remove e- from s and therefore more energy required…. greater f.i.e

Question 10

metallic character

Answer 10

tendency of an element to lose electrons and f orm cations

Question 11

electronegativity

Answer 11

ability to attract electrons towards itself.

Question 12

what increases as effective nuclear charge increases

Answer 12

first ionisation energy
electronegativity