Structure and Bonding Flashcards
What are Electron shells made up of
Sub-Shells
What are sub- shells made up of
Orbitals
How many electrons can an orbital hold
Two
What does a Nucleus contain
Protons and neutrons
What are the subatomic particles
Protons- Have a positive charge and found in the nucleus
Neutrons- Have no charge and found in the nucleus
Electrons- Have a negative charge and they orbit the nucleus int the shells
What is the atomic number?
The number of protons
What is the mass number?
Number of protons and neutrons
What is an isotope?
Same number of protons different number of nuetrons
How many electrons can shell 1, 2 and 3 hold?
Shell 1- 2 electrons
Shell 2- 8 electrons
Shell 3- 18 electrons
Describe S orbitals
Each energy level has one s-orbital
Can hold up to 2 electrons
Higher electron density near the nucleus
First two electrons of an atom will use this as its the lowest available energy level
Describe P orbitals
There are three p-orbitals in an energy level
Can hold up to 6 electrons
Describe D orbitals
At the third energy level there are five d-orbitals
Can hold up to 10 electrons
What order does the s, p, d orbitals go in?
1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → 5s → 4d
What is ionic bonding?
A bond between a metal and a non-metal
Electrons are transferred
What happens during ionic bonding?
Metal atoms lose electrons to become positively charged ions called cations
Non-Metals gain electrons to become negatively charged ions called anions
What is an ionic bonding electrostatic attraction?
Attraction between oppositely charged ions
What are some ionic bonding properties?
High melting and boiling points
Conductive when molten or dissolved in water
What is covalent bonding?
Bond between non-metals where electrons are shared
What are the different types of covalent bonding?
Single bond-one pair of electrons shared
Double bond-two pairs of electrons shared
Triple bond-three pairs of electrons shared
What are some properties of covalent bonds?
Low melting and boiling points
Poor conductivity
Form molecules or giant covalent structures
What is metallic bonding?
Bonding in metals where electrons are delocalised
What is the structure of metallic bonding?
Positive metal ions lost in ‘a sea of electrons’
What are some of the properties of metallic bonding?
Good electric and thermal conductivity
Malleable
High melting and boiling points
What is Van der Waals forces?
Weak forces between molecules which increase with molecular size
What is Dipole-Dipole forces?
Attraction between polar molecules
What is hydrogen bonding?
Strong intermolecular force when a hydrogen bond to highly electronegative atoms (N, O, F)
Describe a diamond structure
Each carbon atom bonded to four others
Very hard
High melting point
Non-conductive
Describe a graphite structure
Each carbon atom bonded to three others
Layers slide over each other
Conductive due to delocalised electrons
Describe a silicone dioxide structure
High melting point
Found in sand and quartz
What is electronegativity?
Tendency of an atom to attract atoms in a bond
What is a polar bond?
Unequal sharing of electrons due to difference in electronegativity
What is a non-polar bond?
Equal sharing of electrons
What is the relative atomic mass (Ar)?
Weighted average mass of an element’s atoms compared to 1/12 the mass of a carbon-12 atom
What is relative molecular mass (Mr)?
Sum of relative atomic masses of all atoms in a molecule
How do you calculate the Mr?
the sum of the relative atomic masses of the atoms in the numbers shown in the formula
What is a Mole?
Unit of amount of substance in chemistry; 1 mole = 6.022×10’23 particles (Avogadro’s constant).
What is the molar mass (g/mol)?
Mass of 1 mole of a substance
Equal to the Mr
What is the formula to find Moles?
Number of moles = mass (g) / molar mass (g/mol)
How do you convert moles to particles?
Particles = moles × Avogadro’s constant
How do you calculate the mass?
Mass (g) = moles × molar mass
What is the formula to calculate the volume of gases?
Volume (dm³) = moles × 24
What is the formula for concentration?
Concentration (mol/dm³) = moles / volume (dm)
What equation contains moles, concentration and volume?
Moles = concentration (mol/dm³) × volume (dm³)
What is the empirical formula?
Simplest whole-number ratio of atoms in a compound
Find by dividing moles of each element by the smallest mole value
What is the molecular formula?
Actual number of atoms of each element in a molecule
Find by multiplying the empirical formula by a whole number so the molar mass matches the molecular mass
How do you balance an equation?
Make the same number of each type of atom on both sides of the equation
Write the unbalanced equation.
Balance each element one at a time, adjusting coefficients.
Double-check for equal atoms on each side.
What is the percentage yield?
Measures efficiency of a reaction
What is the formula for percentage yield?
PercentageYield= theoreticalyield/ actualyield×100%
What is the actual yield?
Mass obtained from the experiment
What the theoretical yield?
Mass calculated based on stoichiometry
What factors affect yield?
Incomplete reactions
Side reactions
Losses during recovery
