Chapter 1 - Steven Flashcards
What is the symbol of the proton?
P
What is the symbol of a neutron?
n
What is the symbol of an electron?
e-
What is the relative mass of a proton?
1
What is the relative mass of a neutron?
1
What is the relative mass of an electron?
1 / 1840
What is the relative charge of a proton?
+1
What is the relative charge of a neutron?
0
What is the relative charge of an electron?
-1
Where are protons located in the atom?
In the nucleus of the atom
Where are neutrons located in the atom?
In the nucleus of the atom
Where are electrons located in the atom?
In energy levels surrounding the nucleus
What does the nucleus contain?
Protons and neutrons
What is the atomic number?
The number of protons and electrons
What is the mass number?
The number of protons + number of neutrons
What are isotopes?
Different forms of the same element with different masses
What do all isotopes contain?
The same number of protons
What is the relative isotopic mass?
The mass of an atom of an isotope compared with 1/12th the mass of an atom of carbon-12
Why is the mass number and relative isotopic not always the same?
Because the isotopic mass number is not always a whole number as it is relative to the mass of carbon-12.
What is the relative atomic mass?
The weighted mean mass of an atom of an element compared to 1/12 of the mass of an atom of carbon-12.
What is the difference between the atomic mass and the isotopic mass?
The isotopic mass is from 1 isotope, whereas the atomic mass is taken from all the isotopes
What does a mass spectrometer measure?
The masses of atoms and molecules
What is the molecular ion peak?
The peak with the highest mass:intensity ratio on the spectrum
What are quantam shells?
Well-defined energy levels that
Where is the 1st quantam shell located?
In the region closest to the nucleus
What is the relative molecular mass?
The average mass of a molecule or formula, compared to 1/12 the mass of carbon-12
How do you work out the relative atomic mass of an element from its isotopic abundances?
1) Multiply each relative isotopic mass by its % abundance and add up the results
2) Divide by 100
What is a mass spectra produced by?
Mass spectrometers
List 2 things that mass spectrometers can tell us:
- The relative isotopic mass
- The abundances of different elements
What does ‘m/z’ stand for?
The mass/charge ratio
What do electrons move round the nucleus in?
Quantum shells
Which have higher energy levels, shells near or far from the nucleus?
Shells far from the nucleus
What do subshells contain?
Different numbers of orbitals, which can hold up to 2 electrons
How many orbitals does an s sub shell contain?
1
How many orbitals does a p sub shell contain?
3
How many orbitals does a d sub shell contain?
5
How many orbitals does an f sub shell contain?
7
How many electrons are in shell 1?
2
How many electrons are in shell 2?
8
How many electrons are in shell 3?
18
How many electrons are in shell 4?
32
What is an orbital?
The bit of space that an electron moves in
What is spin-pairing?
When the electrons in each orbital have to spin in opposite directions
What shape are s-orbitals?
Spherical
What shape are p-orbitals?
Dumbell
What angles are the 3 p-orbitals at to each other?
At right angles
Do electrons fill orbitals singly or pair up?
They fill orbitals singly first
What do electrons fill up first?
The lowest energy subshells
What fills up first, the 4s subshell or the 3d subshell?
The 4s subshell
What is the s-block of the periodic table?
Groups 1 + 2
What is the d-block of the periodic table?
The transition metals
What is the p-block of the periodic table?
Groups 3 to 7
What is electromagnetic radiation?
Energy that’s transmitted as waves
As you go along the EM radiation, what does the radiation increase in?
Frequency
If an atoms’s electrons take in energy from the surroundings, what happens?
They can move to higher energy levels further from the nucleus
How do electrons release energy?
By dropping from higher energy levels to a lower one
What does an emission spectrum show you?
The frequencies of light emitted when electrons drop down energy levels
As the number of energy levels increases, what decreases?
The distance between the set of lines on the emission spectra
What are the 4 basic principles about electron shells?
- Electrons Only exist in fixed orbits of shells
- Each shell has a fixed energy
- Radiation has a fixed frequency
- When an electron moves between shells, EM radiation is emitted or absorbed
Are energy levels discrete or continuous?
Discrete
What does ‘discrete’ mean?
There is no in-between stage
What is the 1st ionisation energy?
The energy needed to remove 1 electron from each ato in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ atoms
What are the 3 factors that affect ionisation energy?
- Nuclear charge
- Electron shell
- Shielding
How does nuclear charge affect ionisation energy?
The more protons there are in the nucleus, the stronger the atrraction to the electrons
How does the elctron shell affect ionisation energy?
Attraction falls off rapidly with distance
How does shielding affect ionisation energy?
As the number of electrons between the outer electrons and nucleus increases, the outer electrons feel less attraction to the nucleus.
What does a high ionisation energy mean?
There is a strong attraction between the electronq and the nucleus, so more energy is needed to overcome the attraction and remove the nucleus
As you go down a group in the periodic table, what happens to the ionisation energies?
They fall
What is the 2nd ionsiation energy?
The energy needed to remove 1 electron from each ion in 1 mole of gaseous 1+ ions to form 1 moles of gaseous 2+ ions
What is the equation for the nth ionsiation energy?
X^n+1 —> X^n+ +e-
What happens to the atomic radius as you go across a period?
It decreases
Does the ionisation energy increase or decrease as you go across a period?
It increases
What is the drop in ionsiation energy between groups 5 and 6 due to?
-The electron repulsion
As you go across a period, what happens to the type of bond formed between the atoms of the element?
The type of bond changes
As the type of bond changes as you go across a period, what does this affect?
The melting and boiling point trend
For metals, what happens to the melting and boiling point as you go across a period?
They increase
What happens to the metallic bonds in metals as you go across a period?`
They get stronger
Why do the metallic bonds in metals get stronger as you go across a period?
The metal ions have an increasing number of delocalised electrons and decreasing radius, so there is a stronger attraction between the metal ions and the electrons
Why do carbon and silicon have high melting and boiling points?
Giant covalent lattice, meaning they have strong covalent bonds.
Why do the elements with simple molecular structures have low melting and boiling points?
London forces are easily overcome as they are weak
Why do the noble gases have low melting and boiling points?
They exist as individual atoms, resulting in weak London forces
