1.2 Flashcards
Positive ion
Cation
Negative ion
Anion
What is an alpha particle
Clusters of 2 protons and 2 neutrons
Helium nuclei
What is a B particle
Fast moving electron
What is gama rays
High energy electromagnetic radiation
What is a positron
Anti electron
Positive B particle
What happens during electron capture
Proton rich nucleus absorbs an inner shell electron
The electron combines with a proton to form a neutron
Define half life
Time taken for the radioactivity of a radioisotope to fall to half its original value
What is an atomic orbital
Region in an atom that can hold up to 2 electrons with opposite spins
Region of space around the nucleus where there is a high probability of finding an electron of a given energy
Number of protons =
- atomic number
* number of electrons
Number of neutrons =
Mass number - atomic number
What is atomic number
Number of protons in the nucleus of an atom
What is mass number
the number of protons + the number of neutrons in the nucleus of an atom
What is an isotope
atoms having the same number of protons but different numbers of neutrons
Why do electrons in an orbital have opposed spins
Minimises the effect of repulsion
S orbital
Spherical
2 electrons
P orbital
Dumb-bell shape
3 at right angles
6 electrons
Which is filled first 4s or 3d?
4s
Which configuration numbers are not as expected
Chromium and copper
Both end in 4s1
What is the molar first ionisation energy
Energy required to remove one electron from each atom in one mole of its gaseous atoms to form one mole of gaseous ions
What is the equation to show the first ionisation energy
X(g) –> X+(g) + e-
What are the three factors that affect ionisation energy
Nuclear charge
Electron shielding
Distance of outer electron from nucleus
Nuclear charge effect on ionisation energy
Greater nuclear charge = greater attractive force on outer electron
Electron shielding effect on ionisation energy
More filled inner shells or subshells = smaller attractive force on the outer electron
Distance of outer electron from nucleus effect on ionisation energy
Greater distance = smaller attractive force on outer electron
What is electron shieldinh
Repulsion between electrons in different shells
Inner electrons repel outer shell electrons
What is successive ionisation energies
Measure of the energy needed to remove each electron in turn until all the electron are removed from an atom
Give the third ionisation energy of sodium
Na2+(g) —> Na3+ + e-
Why do successive ionisation energies always increase
- greater effective nuclear charge as same number of protons holding fewer electrons
- less electron shielding with each electron
- as distance decreases the nuclear attraction increases
What does a large increase in successive ionisation energies show
Electron has been removed from a new shell closer to the nucleus and gives the group to which the element belongs
Which group is an atom that has a large energy jump between 3rd and 4th ionisation energy
Group 3
What is light
A form of electromagnetic radiation
Equation for frequency and wavelength of light
C = f(lamda)
C is speed of light
Equation for frequency of electromagnetic radiation and energy
E = hf H = plancks contant
If frequency increaes
Energy increases
Wavelength decreases
Describe absorption spectra
Energy is absorbed from a light causing electrons to move from a lower energy level to a higher one
Dark lines against a bright background
Describe emission spectra
Energy is emitted as electrons fall back from higher energy level to a lower one
Coloured lines against a black background
State what happens in the nucleus of an atom when a beta particle forms
Neutron decays to form a proton and an electron
The nucleus emits the electron
