Unit 1, periodic trends

Question 1

Trend #1- Atomic radius

Answer 1

Decreases from left to right across periods (strength of nucleus increases with more protons- with a stronger pull on the outer electrons)

Increases from top to bottom down groups (number of energy levels increases, further and further from the nucleus, increasing the size of the atom)

Question 2

Atomic radius

Answer 2

an estimate of the size of an atom from its nucleus to its outermost electrons

Question 3

Ionic radius

Answer 3

when an atom loses outer electrons it loses an entire energy level; therefore it becomes smaller, positive cation

a negative ion (anion) has more electrons than protons, the electrons repel each other and the effect of the nuclear charge is shared among more electrons (anions are bigger than their original atoms)

Question 4

Ion

Answer 4

formed when an atom loses or gains electrons

Question 5

Cation

Answer 5

positive ion, lost electrons, metals

Question 6

Anion

Answer 6

negative electron, gained ions, non-metals

Question 7

Trend #2 Ionization Energy

Answer 7

Ionization energy increases from left to right across a period (since atomic radius decreases, the valence electrons are held closer together, needing more energy to remove)

Ionization energy increases from bottom to top of a group (radius decreases, so more energy is required to remove the valence electrons because there is a greater attractive force)

Question 8

Ionization energy

Answer 8

the energy reeded to remove a valence electron from an atom or ion in its gaseous state

Question 9

Electron Affinity

Answer 9

the energy released when a gaseous atom gains an electron

Question 10

Trend #3 Electron affinity

Answer 10

large values of ionization energy means that removing an electron is difficult and requires a lot of energy

Increases from left to right

Increases from bottom to top

Question 11

Electronegativity

Answer 11

the attraction an atom has to the electrons it is covalently sharing

Question 12

Trend #4 Electronegativity

Answer 12

Down a group (decreases)- there are more protons and a greater number of energy levels. The inner electrons are creating a shielding effect resulting in less attraction to the nucleus

Across a period (increases) the radii decreases therefore electrons are held closer to the nucleus since there is a stronger pull, so shared electrons in a bond are attracted more greatly

Question 13

delta E number line

Answer 13

0-0.4 : non-polar, pure covalent bond, bonding e are shared equally
0.4<x<= 1.7: polar bond, e are not shared equally, partial negatives (biggest number) and partial positives
1.7< : ionic bond or extremely polar covalent bond