Atomic structure Flashcards
What are the 3 subatomic particles?
Proton, neutron, electron
What are the charges and location of protons and electrons?
Proton: +1, in the nucleus
Electron: -1, in orbitals around the nucleus
What is the role of neutrons in the nucleus?
They add mass and help stabilise the nucleus
What is an ion?
An atom or molecule with a charge due to losing or gaining electrons
What is a cation?
A positively charged ion formed by losing electrons
What is an anion?
A negatively charged ion formed by gaining electrons
What is an electrolyte?
A substance that conducts electricity in solution by releasing ions
What is the maximum number of electrons in an S orbital?
2
What is the order of orbital filling?
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f……
What are the 4 quantum numbers?
n (shell)
I (subshell)
m (orbital orientation)
s (spin)
Name the state symbols
aq (Aqueous)
s (Solid)
g (Gas)
l (Liquid)
What is the formula for concentration in mol/dm³?
C = n/V
What is the formula for moles using mass?
n = m/Mr
How many particles are in one mole? (Avogadro’s number)
6.022 × 10²³
What is the molar volume of gas at room temp?
24 dm³/mol (at 20°C and 1 atm)
What is the formula to convert g/dm³ to mol/dm³?
C = m/(Mr x V)
What is ionisation energy?
The energy needed to remove one mole of electrons from one mole of gaseous atoms
Why is the second ionisation energy higher than the first?
Because it’s harder to remove an electron from a positively charged ion
What factors affect ionisation energy?
Atomic radius, nuclear charge, shielding, orbital stability
How does atomic radius affect ionisation energy?
Larger atoms = lower ionisation energy (electrons are further away)
How does nuclear charge affect ionisation energy?
More protons = higher attraction = higher ionisation energy
How does shielding affect ionisation energy?
More inner shells = more shielding = lower ionisation energy
Why is it easier to remove paired electrons?
They repel each other slightly
What is relative atomic mass (Ar)?
The average mass of isotopes compared to 1/12 of carbon-12
What is the relative molecular mass (Mr)?
The sum of Ar values in a molecule
What is radioactivity?
Spontaneous emission of radiation from an unstable nucleus
What are the three types of radiation?
Alpha, Beta, Gamma
What is alpha radiation?
2 protons + 2 neutrons (He nucleus) (low penetration)
What is beta radiation?
High-speed electron from nucleus. (medium penetration)
What is gamma radiation?
High-energy wave, no mass or charge. (high penetration)
What is a radioactive isotope?
An unstable isotope that emits radiation to become stable
What is a half life?
The time required for a substance to reduce to half of its initial value
How do you calculate decay?
N = N₀ × (½)ⁿ, where n = number of half-lives
