Atomic Structure and Bonding

Question 1

atoms are comprised of

Answer 1

protons
electrons
neutrons

Question 2

protons

Answer 2

the number of protons in the nucleus identifies the atom and therefore the element

Question 3

neutrons

Answer 3

can vary without changing the element

Question 4

electrons

Answer 4

found in clouds/orbitals around the nucleus of the atom, determines the chemistry of the element

Question 5

nuclear strong force

Answer 5

holds protons and neutrons together
very strong but short ranged interaction

Question 6

ions

Answer 6

formed when electrons are added or removed from a neutral atom, but the protons remain the same
carry a charge

Question 7

negative ions

Answer 7

contain more electrons than protons

Question 8

positive ions

Answer 8

contain fewer electrons than protons

Question 9

work

Answer 9

energy required to move from the lower energy state

Question 10

potential energy

Answer 10

energy expended to return to lower energy state

Question 11

ionic bonding

Answer 11

donation of electrons that results in charged atoms
sodium loses an electron to a chlorine atom and makes Na positive and chlorine negative

Question 12

covalent bonding

Answer 12

electrons are shared between atoms
substances are held together by interactions between atomic orbitals and the electrons occupying the orbitals on adjacent atoms

Question 13

metallic bonding

Answer 13

metals have low ionization energy - results in delocalized valence electrons, creating a high energy sea/cloud of electrons

electrons hold the positive atoms in place, giving material structure and certain characteristics

sharing of free electrons among a structure of positively charge ions

Question 14

electronegativity

Answer 14

the ability of an atom in a molecule to attract shared electrons

electrons are pulled towards the more electronegative atoms

Question 15

Linus Pauling polarity scale

Answer 15

<0.4 = zero –> pure covalent
0.4-1.7 = intermediate –> polar covalent
>1.7 = large –> ionic

Question 16

Linus Pauling polarity scale trend

Answer 16

as covalent character increases, ionic character decreases

Question 17

diatomic molecule

Answer 17

H2
non polar
symmetrical electron sharing

Question 18

non-symmetrical molecule

Answer 18

HCl
polar
unsymmetrical electron sharing

Question 19

secondary bonding/intermolecular forces

Answer 19

non-covalent bonds
electrons are not shared
result of charge variations
weaker
two main types: Hydrogen bonds (dipole-dipole - unequal bond sharing), Van der waals (VDW) bonds (dispersion forces - equal bond)

Question 20

hydrogen bonds

Answer 20

results from electrostatic attraction between permanent dipoles created by unequal sharing of electrons in covalent bonding

responsible for density of liquid water being higher than density of ice

Question 21

Van der Waals forces

Answer 21

results from electrostatic attraction between temporary dipoles created by nearly equally shared electrons in covalent bonding

responsible for holding collections of molecules together in bulk materials