Topic 1 - Elements and Periodic table Flashcards
Atoms
building blocks of matter, smallest particle that can exist and still be a substance have a nucleus and an electron cloud
Elements
materials that contain just one type of atom
Compounds
materials that contain different types of atoms 2 or more different types of atoms bonded together in a fixed ratio.
mass number
the total number of protons and neutrons in the nucleus. A
Atomic number
the number of protons and electrons in the nucleus of an atom. = z
Nucleons
the subatomic particles that make up the nucleus - protons and neutrons.
Periodic Table - Group
Verticle
Periodic Table - Period
Horizontal
Electrostatic attraction
the positive and negative charges are attracted to each other
Isotopes
same protons, different neutrons,
Ions
Cations (positive), Anions, lose=+, gain=-. number then charge
Emission Spectra
heat provides energy, the electrons become excited and then the electrons can jump into different shells
How many lines would arise if an electron jumped to the third excited state
6
What type of transition results in an emission spectrum
electrons transition from high to low energy
How to tell the max electrons in each shell
2n^2, n = shell number
Bohr’s theory proposed that…
electrons move around the nucleus in fixed orbits, each of which has a different energy level
what is required for an electron in an atom to move from a lower energy to a higher energy level?
absorption of energy
what happens when an election returns to a lower level
it releases photos as it returns to its ground state
what is responsible for the colour released
metals
Why only one ground state
Most stable, their normal energy levels
emission definition
elements releasing different photos of colour as electrons go back down to ground state
which electrons are likely to be excited in a flame test first
Valence electrons - held so losely
the electron configuration of excited sodium (11)
2, 8, 0, 1
how does a spectroscope work
it uses diffraction to separate the different colours of light
isotopes are…
radioactive, unstable, different physical properties but same chemical properties
how many times larger is the atom compared to its nucleus
10,000 - 100,000 times
what form of energy is emitted when an electron moves from a higher energy shell to a lower energy shell
as coloured light or electromagnetic radiation
Atomic Theory
atoms are not indivisible or indestructible, they are made of even smaller subatomic particles
