Topic 1 - Atomic Structure & The Periodic Table Flashcards
Meaning Relative Atomic Mass (Ar)
The weighted mean mass of an atom of an element, compared to 1/12th of the mass of an atom of carbon-12
Meaning Relative Isotopic Mass
The mass of an atom of an isotope, compared to 1/12th of the mass of carbon-12
Meaning Relative Molecular Mass (Mr)
The mean mass of a molecule, compared to 1/12th the mass of an atom of carbon-12
Name all of the orbitals
s, p, d, f
Describe the s orbital
Has 1 orbital, so can hold 2 electrons
Describe the p orbital
Has 3 orbitals, so can hold 6 electrons (2x3)
Describe the d orbital
Has 5 orbitals, so can hold 10 electrons (5x2)
Describe the f orbital
Has 7 orbitals, so can hold 14 electrons (7x2)
Which shape does an S orbital have
Spherical shape
Which shape does a p orbital have
Dumb-bell shaped
Give the electron configuration of iron
Give the electron configuration of calcium +2
Give the electron configuration of iron +3
Give the electron configuration of copper
State the different radiations in order of the electromagnetic spectrum
Radio waves, micro waves, infrared, visible light, ultraviolet, X-rays, gamma rays
When do electrons become excited
When electrons absorb energy (endothermic) as it moves up an energy level
In an atomic emission spectra, why do the lines get closer
Because energy and frequency increases
When do electrons show ultraviolet radiation
When an electron falls to the ground state (n=1)
When do electrons show visible radiation
When an electron falls to the second energy level (n=2)
When do electron show infrared radiation
When electrons fall to the third energy level (n=3)
Meaning ionisation
The minimum amount of energy required to remove 1 mole of electrons from 1 mole of atoms in a gaseous state
What are 3 factors of ionisation
Shielding, nuclear charge, atomic size
How does shielding affect ionisation
The more electron shells between the positive nuclei and the negative electron thats is being removed, the less energy required to ionise because theres a weaker attraction
How does nuclear charge affect ionisation
The more protons in the nucleus, the larger the attraction between the nucleus and the outer electrons. This means more energy is needed for ionisation
How does atomic size affect ionisation
The bigger the atom, the further away the outer electrons are from the nucleus. The attractive force between the nucleus and the outer electrons reduces, so less energy is needed to ionise an electron
Why does the atomic radii decrease across a period
The further across a period, there higher number of protons in the nucleus. This pulls the outer electrons further towards the nucleus. Shielding has no effect
Why does the melting points of metals increase across a period
As the metals have more protons in their nucleus, there’s an increase in positive charge. So, there’s an increased number of delocalised electrons and smaller atomic radii. This means stronger metallic bonds, so more energy is needed to bream the binds.
Explain why silicon (S8) has the highest melting point in period 3
Silicon is a giant covalent structure. This means it has many strong covalent bonds that hold the silicon atoms together. Thus, a large amount of energy is needed to overcome these string covalent bonds
Why does sulfur have a lower melting point than phosphorus, even though it’s further across period 3
Sulfur has a larger simple molecular structure and has larger london forces than phosphorus
Why does argon have the lowest melting point in group 3
Argon only exists as individual atoms as its a noble gas, so it has small london forces
