chapter 7- trends in the periodic table

Question 1

atomic radius

Answer 1

half the distance between the nuclei of two atoms of the same element that are joined together by a single covalent bond

Question 2

2 reasons values of atomic radius increase down the groups

Answer 2

• extra energy level further from nucleus
  -screening effect of inner electrons

Question 3

screening effect

Answer 3

happens when inner electrons in an atom block/shield the outer electrons from the pull of the nucleus (nuclear charge decreases)

Question 4

2 reasons values of atomic radius decrease across a period

Answer 4

• increase in effective nuclear charge (due to more protons, stronger pull of electrons)
• no increase in the screening effect

Question 5

first ionisation energy of an atom

Answer 5

the minimum energy required to completely remove the most loosely bound electron from a neutral gaseous atom in its ground state
*** include formula

Question 6

2 reasons inonisation energy decreases down the groups

Answer 6

• increasing atomic radius
  -screening effect of inner electrons

Question 7

2 reasons vale of first ionisation energy increase across periods

Answer 7

• increasing effective nuclear charge
  -decreasing atomic radius

Question 8

exceptions to trends in ionisation energy

Answer 8

any sublevel that is completely full or half full (due to having extra stability and slightly higher ionisation)
Be, Mg (full), N, P (half full)

Question 9

second ionisation energy

Answer 9

the energy which is required to remove an electron from an ion with one positive charge in the gaseous state
** must include formula