Atomic Structure and the Periodic Table Flashcards
Atom
The smallest part of an element that can exist
Radius of atom
0.1nm
Subatomic particles in atom nucleus
- protons
- neutrons
Radius of nucleus of atom
1 x 10⁻¹⁴ m
Size of atom nucleus to radius of atom
1/10000
Charge of nucleus of atom
Positive
Where is mass concentrated in atom
Nucleus
Where are electrons in atom
Orbiting nucleus on shells
Charge of proton
+1
Relative mass of proton
1
Charge of electron
-1
Relative mass of electron
1/1840
Charge of neutron
0
Relative mass of neutron
1
Charge of an atom
Neutral
Why is charge of atom neutral
Same of number of protons and electrons, their charges cancel out
What does atomic number tell you
Number of protons in an atom
What does mass number tell you about an atom
Number of protons and neutrons
How to find number of neutrons in an atom
Atomic mass — atomic number
Element
Substance made up of one type of atom
What decides what type of atom it is
Number of protons
How many elements are there
About 100
Isotopes
Atoms of an element with the same number of protons but a different number of neutrons
Relative atomic mass
Average mass of an element, taking into account all isotopes that make up an element
Relative atomic mass formula
sum of (isotope abundance X isotope mass number)
—————————————————
sum of abundances of all isotopes
Compound
Substances formed from 2 or more elements with the atoms in fixed proportions throughout the compound, held together by chemical bonds
How are compounds made
Elements reacting together
How are compounds separated into elements
chemical reactions
How are bonds made
Giving away, taking or sharing electrons
Ion
charged particles that have gained or lost electrons, making them positively or negatively charged
What happens to metal atoms in atomic bonding
- lose electrons
- form positive ions
What happens to non-metal atoms in atomic bonding
- gain electrons
- form negative ions
What does a compound formed of non-metals consist of
- molecules
- each atom covalently bonds to another
Mixture
Substance made from two or more elements or compounds that aren’t chemically bonded
How are mixtures separated
Physical methods
What are the physical methods
- filtration
- crystallisation
- simple distillation
- fractional distillation
- chromotography
Air
Mixture of gases, mainly nitrogen, oxygen, carbon dioxide and argon, easily separated
Crude oil
Mixture of different length carbon molecules
Properties of a mixture
Mixture of properties of separate parts
Paper chromatography practical
- draw baseline in insoluble pencil 1cm from bottom of the paper
- add ink spot to line and place paper in solvent, not touching ink
- place lid on container to stop evaporation
- solvent seeps up paper
- dyes move up paper at different rates, seperating
- if dyes are insoluble they stay on baseline
- taken paper out of beaker to dry
- have a chromatogram
When is filtration used
- to separate an in insoluble solid from a mixture
- purification
Filtration
- fold filter paper into cone and place in funnel
- place funnel in conical flask
- pour solution through
- substrate filters through, residue left in filter paper