Year 10 AT1 Flashcards
atoms
atoms are made of protons, neutrons and electrons. they make up everything in existence.
nucleus
found in the centre of the atom. Holds the protons and neutrons inside of it.
electrons
- negatively charged (-1)
- found orbiting the atom’s nucleus (on the shells)
- relative mass is approx 1/1836 or 0
protons
- positively charged (+1)
- found in nucleus
- relative mass is 1
neutrons
- neutral charge (0)
- found in nucleus
- relative mass is 1
groups
each element on the periodic table is apart of a group or family due to similar reactiveness and/or chemical properties. they go by column and there is 18 of them.
periods
all elements in the same period have the same number of atomic shells/orbitals. they go by row
alkali metals (group 1)
have 1 valence electron, are shiny, are soft, also called the basic family.
alkali earth metals (group 2)
never found uncombined in nature, they have two valence electrons.
transition metals (groups 3-12)
good conductors of heat and electricity.
halogen family (group 17)
they have 7 valence electrons, most active non-metals, only need one electron to fill their outermost shell, they react with alkali earth metals to form salt.
noble gasses/inert gasses (group 18)
the noble gasses are colourless and unreactive (inert), their outermost shells are full, and are found in small amounts in the earth’s atmosphere (atmosphere is made up of 78% nitrogen 21% oxygen 1% carbon dioxide)
rare earth metals
there’s thirty of them in the lanthanide and actinide series in total
gasses
all gasses are diatomic meaning they have two atoms (E.G. O2, H2, N2, Cl2 etc)
electron shells
the total number of electrons a shell can hold is given by the formula 2n to the power of two (n is the number of shells)
- 1st shell holds 2
- 2nd shell holds 8
- 3rd shell holds 18
electron configurations
electron configurations show the electrons arrangement while in the ground state (E.g. Berylliums electron configuration is 2,2)
ground state
the ground state is then the atom has its lowest possible energy and is most stable (the atoms normal state).
excited state
electrons are temporarily put in a satte of high energy (very unstable). the electrons jump to other shells releasing energy (flame, light, or sparks). it will eventually go back to normal (ground sate).
ions
when we change an atoms total number of electrons.
isotopes
an atom thats had its number of neutrons changed, ultimately changing is atomic mass. the element stays the same but just has a new mass (E.g. carbon-12 is the ‘normal’ isotope, whilst carbon-13 is the ‘different’ isotope)
radio-isotopes
some isotopes have an imbalance in it’s total number of protons causing instability in the nucleus, which will make excess energy that undergo decay. they can release particles and/or electromagnetic radiation from their nucleus resulting in nuclear decay.
types of nuclear radiation
- alpha radiation (a)
- beta radiation(B)
- gamma radiation (Y)
alpha radiation
nucleus needs to become stable, so it throws a cluster made up of 2 protons and 2 neutrons to stabilize itself. the cluster of protons and neutrons are called alpha particles. alpha particles are a helium nucleus.
beta radiation
a beta particle occurs when a atom has a imbalance in neutrons and protons so a neutron turns is turned into either a proton or electron to balance itself.
