atomic structure and the periodic table Flashcards
what is an elemnt
an elemnt is a substance made up of only one type of atom
what is a compound
two or more elements combined chemically
do compounds have the same properties as their constituent elements
no they have different properties
what is a mixture
a mixture consists of two or more elements not chemically combined together. it does have the same properties as its constituent materials
what are the methods mixtures can be seperated
filtration, crystallisation, simple distillation, fractional distillation, and chromatography
describe and explain simple distillation
- used to separate liquid from a solid.
- the liquid boils of and condenses in the condenser.
- the thermometer will read the boiling point of the pure liquid
- you keep the liquid
what is a seperating funnel
- appratus for separating imiscble liquids.
- two immiscible liquids of two different densities will form two distinct layers in the separatory funnel.
- we can run off the bottom layer into a seperate conainer.
describe the plum pudding model
the atom is a ball of positive charge with negative electrons embedded in it.
describe the nuclear model
the nuclear model suggests that electrons orbit at specific distances on shells , it came about from the alpha scattering experiment.
what did james chadwick provide energy for
the existance of neutrons in the nucleus
describe the structure of an atom
the atom has a small centural nucleus made up of protons and neutrons, which electrons orbit on shells
releative charges of protons neutrons and electrons
proton - 1
neutron - 0
electron - -1
releative masses of protons neutrons and electrons
proton -1
neutron - 1
electron - very small
why are atoms electrically neutral
they have the same number of electrons and protons
what is atomic number
the number of protons in the nucleus
where is the majority of the mass in the atom
the nucleus
what is the mass number
the total number of protons and nuetrons
what is an isotope
atoms of the same element with the same number of protons but a different number of neutrons. they have the same chemical properties as the have the same chemical structure
what is relative atomic mass
the avarage mass value which takes into account the mass and abundance of isotopes o an element on a scale where the mass of 12C is 12
what are ions
- ions are charged particles
- they are formed when atoms lose elecrtons (postive ions) or gain electrons (negative electrons)
compare the properties of metals and non - metals
what is fromed when a metal rects with a non-metal
an ionic compound (made up of posotive and negative ions)
what is formed when a non-metal reacts with a non-metal
a molecular compund containing covanlently bonded atoms. atoms share electrons as opposed to transferring electrons between each other.
what is a soulut what is a solvent
-solute = a substance that is dissolved in a solvent together they from a solution
what does miscible and immiscible mean
miscible refers to substances that mix together e.g water and alcohol.
immiscible means they do not mix e.g water and oil
are elemnts in the same group similar
yes they may have similar chemical properties as they have the same number of atoms on the outer shell
what are group 0 known as
noble gases
what happens in the shell number when you move down the group
the number of shells increases
what made is possible to explain why the order absed on atomic wheights is not always correct
isotopes
