radiation, atomic mass and structure Flashcards
describe the general model of an atom
has a nucleus composed of positively charged protons and neutral neutrons surrounded by an electron cloud equal to the amount of protons if a stable element
difference between mass number and atomic number
mass number is = to relative atomic mass and atomic number is no. of protons in the element or isotope
what is an isotope
Isotopes are derivatives of elements that have the same no. of protons but a different number of neutrons.
Isotopes are often radioactive.
describe the three types of radiation
alpha: loss of a helium atom
beta: loss of an electron
gamma: waves
order the types radiation from most to least radioactive
gamma > beta > alpha in radioactivity and penetration
what is the strong nuclear force
The strong nuclear force is essentially the energy that holds the world together.
It is independent of charge and acts between protons and neutrons, holding them together.
what is relative isotopic mass
the average mass of an element with consideration of all its isotopes and their abundances, this is the mass number on the periodic table
waht is relative molecular mass
sum of the weights of the atoms as given in the molecular formula
e.g HCl = 1 + 35.45 = 36.45 u or g depending on mols
what is percentage mass ratio
it is the ingredient box of a compound, basically percentage of mass in a compound per element
define ionisation energy
ionisation energy is the energy required to remove an electron from an atom in the gaseous state
is there more than one ionisation energy?
There is more than more than one ionization energy if there is more than one electron in the shell
define first ionization energy
The first ionization energy is the energy required to remove the first electron from the gaseous base
as an element gains more electron shells what happens to the ionisation energy
becomes lower
what is a flame test
a qualitative assessment to confirm metals are present in certain substances
what is the ground state of an atom
the ground state of an atom is the lowest energy state of an atom
how are electrons arranged energy wise to the atom
Electrons in an atom tend to be arranged in a way so that the energy of the atom is as low as possible
what is the excited state of the atom
Excited state is when the potential energy is higher than ground state
is the absorption spectrum more colour or black
colour as it absorbs more colours
is the emission spectrum more colour or black
black as it emits only certain spectra
note
emission spectrum is the opposite of absorption spectrum, essentially equals to a whole colour spectrum
REVISE
electron configuration and orbitals
outline bohr model
Describes electrons existing in stable energy levels at different radial distances form the nucleus
These energy levels are referred to as electron shells
Pattern = 2n^2
Electrons fill the lowest energy levels first
