Atomic Theory 2: periodic trends, chemical bonding, and molecular structures

Question 1

What do the electrostatic forces of attraction and repulsion do

Answer 1

influences properties such as atomic size, ionization energy, and electronegativity

Question 2

Atomic size down group

Answer 2

Increases when moving down a group
Number of shells increase, so valence electrons are farther from nucleas.

Question 3

What is the shielding effect

Answer 3

Repulsion be e- from lower shells, increases atomic size

Question 4

Atomic size across period

Answer 4

Decreases moving left to right across a period
Number of protons in the nuclear increase = more electrostatic force, electrons pulled closer to nuclear
More e- than protons = harder to pull them to center

Question 5

What is electronegativity

Answer 5

The ability for an atom to draw bonding e- to itself, affected by atomic number and radius

Bigger atoms = less electronegativity
Smaller atoms = more electronegativity

Question 6

Electronegativity down group

Answer 6

Decreases moving down a group
The valence shell is farther from the nuclear, so less attraction between nucleus and e-

Question 7

Electronegativity across a period

Answer 7

Increases moving lef tot right across a period
The more protons added to nuclear, the stronger the pull on e-

Question 8

What is ionization energy

Answer 8

The energy required to remove a valence e- from a neutral atom

Question 9

Ionization energy across a period

Answer 9

Increases left to right across a period
Increase in e- and protons = greater force of attraction = more energy needed to remove them

Question 10

Ionization energy down a group

Answer 10

Decreases moving down a group
Shielding effect (more e- to repel) weakens the force between the valence e- and the nucleus

Question 11

What do negative electron cloud do

Answer 11

Exert repulsive forces

Question 12

how does a chemical bond form

Answer 12

If the attractive forces between the atoms are stronger than the repulsive forces, the two atoms are in a state of lower energy (stable) then when they were apart

Question 13

What is an ionic bond

Answer 13

A bond between two atoms with a big difference in EN, occurs bc of the metals low ionization energy and ENs

Question 14

Where is the force of attraction in a covalent bond

Answer 14

Between a pair of e- and 2 adjacent positive nuclei, all species are electrically neutral

Question 15

Example of nonpolar covalent bond

Answer 15

Hydrogen and hydrogen, EN difference is close to 0 = density of e- cloud is centered between the nuclei

Question 16

What are polar covalent bonds

Answer 16

Covalent bonds between atoms with different EN, results in an unequal sharing of bonding electrons, resulting in a dipole

Question 17

What is a dipole

Answer 17

A partial negative pole and a partial positive pole