chemistry part 1 additional science
- Created by: Connor
- Created on: 12-02-14 18:36
View mindmap
- CHEMISTRY PART 1
- the atom
- neutrons: mass(1) neutral in the nucelus
- protons: mass(1) postitive in the nucleaus
- electrons: no mass negative found in energy levels surrounding nucleus
- the mass number is proton+neutron the proton number is the number of protons and electrons
- particles
- an atom is the smallest particle that matter is made up of
- a molecule is 2 or more atoms that are chemically bonded together
- an element is only made up of one type of atom
- a compound is 2 ore more different types of elements chemically bonded together
- electronic structure diagram
- 1st energy level can hold 2 the others can hold 8
- elements in the same groups have similar chemical properties
- bonding
- ionic bonding occurs when a metal donates an electron(s) to a non metal
- covalent bonding occurs when 2 or more non-metals share electrons to reach a stable noble gas configuration
- macro molecules
- giant covalent structures
- in graphite each carbon atom us bonded to 3 others, free to slide over each other, has free delcoalised electron to carry a current
- diamond is covanelty bonded to 4 other carob atom, alot of energy is required to break it, does not conduct electricity as there is no free delocalised electrons
- ions
- charged atoms due to the loosing or gaining of electrons
- Na becomes Na+ because it looses 1 electron
- Mg becomes Mg-2 because it gains 2 electrons
- structure of a metal
- the outer shell of a metal atom is delocalised, this means the atoms are positively charged ions
- positively charged ions in a sea of negative electrons
- metallic bond is a force of attraction between ions and electrons
- metals are soft because they are arranged in layers and they can slide over each other
- covalent compounds are formed when non-metal atoms react together
- they will conduct electricity if you dissolve them in water or heat them as this will free the ions to carry a current
- nanoscience
- the study of substances from 1 to 100 nanometers
- they make excellent catalysts because they have a high surface area to volume ration
- simple molecules
- they can be a solid, liquid or a gas they have a low melting and boiling point
- they have weak intermolecular forces of attraction they do not conduct electricty
- isotopes
- atoms of the same element that have different mass and neutron numbers
- O16 has 2 more neutrons in its nucleus than O18
- Ar= relative atomic mass=mass number
- Mr= relative formular mass= sum of Ar's
- chromotography
- separates a mixture of liquids between a stationary phase to a mobile phase(different solubility's) the result is a chromatogram
- the retention time is how long it takes to move through the stationary phase
- advantages: accurate, sensitive, quick
- percentage yield: the amount of product we make compared with the amount we should have
- the atom
Comments
No comments have yet been made