Atomic Structure And Periodicity Flashcards
Atom definition
smallest particle of an element.
Element definition
composed of the same type of atom.
Compound definition
two or more elements chemically bonded together.
Molecule definition
two or more atoms covalently bonded together.
Ion definition
Charged particle
Cation definition
Positively charged ion
Anion definition
Negatively charged ion
Nucleon definition
Nucleons are the sub-atomic particles that exist in the nucleus of atoms (protons & neutrons).
Strong nuclear force definition
The strong nuclear force holds together protons & neutrons in the nucleus
Electrostatic forces of attraction definition
Electrostatic forces of attraction exist between any positive and negative particles.
Isotopes definition
Isotopes are atoms of the same element with different numbers of neutrons. (same numbers of protons and electrons)
Relative atomic mass definition
Relative atomic mass (Ar) is the average mass of an atom of an element (taking into account the relative abundances of isotopes) compared to one twelfth of the mass of one atom of carbon-12
Relative isotopic mass
Relative isotopic mass is the mass of an atom of an isotope compared to one twelfth of the mass of one atom of carbon-12.
Atomic number definition
Atomic number (Z) is the number of protons in the nucleus of an atom of that element
What does ‘A’ mean?
A = mass number (no. of protons + neutrons in the nucleus)
Species definition
A species in chemistry is “a substance composed of chemically identical entities”
Relative molecular mass definition
Relative molecular mass (Mr) of a compound is the sum of the relative atomic masses of all the atoms in a molecule compared to one twelfth of the mass of one atom of carbon-12.
Relative formula mass definition
Relative formula mass (Mr) of an ionic compound is the sum of the relative atomic masses of all the atoms in the formula compared to one twelfth of the mass of one atom of carbon-12.
Main shell/ quantum shell definition
A main shell or quantum shell is made up of sub-shells containing orbitals, where electrons are found.
Orbital definition
An orbital is a region of space in an atom containing up to two electrons with opposite spins.
Sub shell definition
A sub-shell is one or more orbitals in the same shell which have the same energy levels.
Block element definition
A _-block element has its highest energy electron in an _ orbital (replace _ with s/p/d/f), i.e…
S block element definition
An s-block element has its highest energy electron in an s orbital
P-block element definition
A p-block element has its highest energy electron in a p orbital
D block element definition
A d-block element has its highest energy electron in a d orbital
Transition metals definition
Transition metals are elements which form at least one stable ion with partially filled d orbitals.
First ionisation energy definition
First ionisation energy is the energy required to remove one mole of electrons from one mole of atoms in the gaseous state. [ M(g) → M+(g) + e- ]
Second ionisation energy definition
Second ionisation energy is the energy required to remove one mole of electrons from one mole of 1+ ions in the gaseous state. [ M+(g) → M2+(g) + e- ]
Successive ionisation energy definition
Successive ionisation energy is the energy required to remove the electrons one after the other.
Periodicity definition
Periodicity is a regularly repeating pattern of atomic, physical and chemical properties with increasing atomic number.
What are the 5 parts of the mass spectrometer?
~ A sample inlet-
~ An ionisation chamber-
~ X (g) + e- → X+ (g) + 2e- An electric field to accelerate-
~ A magnetic field to deflect-
~ Those with greater mass are deflected less than those with smaller mass.
~ The angle of deflection depends on the ______________
What are the uses of the mass spectrometry?
- To determine isotopic composition
- To determine the relative molecular mass of a molecule
- To determine relative atomic mass of an element e.g
- To determine drugs in urine samples-e.g anabolic steroid nandrolene have a unique molar mass
- In the pharmaceutical industry-
- Carbon-14 dating-
What is the definition of fragmentation?
i.e breakdown of X+ into lighter positively charged ions
Nuclear charge definition
The charge of the nucleus
Electron shielding definition
Outer shell electrons don’t experience the force of attraction of nucleus due to the presence of inner shell electrons
What’s the 1st quanta?
Has only 1 orbital, it’s an S and is a sphere. Can take up to 2 electrons with opposite spins
What is the 2nd quanta?
Has 3 orbitals with letter P, dumbell shape can take up to 6 electrons
What other blocks are there other than s and p?
D block- up to 10 electrons and 5 orbitals
F block- up to 14 electrons and 7 orbitals
Order of electron configuration
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d
6s 6p
7s
Goes diagonally from right to left (downwards)
Exceptions for the order of electron configuration
Cr is 3d^5 4s^1 NOT 3d^4 4s^2
Cu is 3d^10 4s^1 NOT 3d^9 4s^2
What is ionisation energy affected by?
~ size
~ nuclear charge
~ shielding
What happens to the ionisation energy as you move down a group?
- ionisation energy decreases
- because size increases, as there are more shells, so forces of attraction increase
- the nuclear charge increases as there’s more protons
- the shielding increases as the shell number increases, less attraction between outer shell electrons and nucleus due to inner shell electrons
What happens to the ionisation energy as you move along a period?
- as you go along the period, the ionisation energy increases
- because the size decreases due to electrons being removed from the same shell
- the nuclear charge increases as there are more protons, and more forces of attraction between the electrons and the protons
- shielding does not change as no new shells are added
Electronegativity definition
Extent that an element can attract a bonding electron to itself, fluorine is the most electronegative element
