F331 Flashcards
What is the mass number?
The number of protons and neutrons
How do you find relative atomic mass?
Average of the masses of the isotopes
What are alpha emissions?
A helium nucleus
What are beta emissions?
An electron
What is gamma emission?
Energy
What occurs in nuclear fusion?
Two light atomic nuclei fuse to form a single heavier nucleus
What is the use of radioisotopes?
Radiocarbon dating (ratio of carbon isotopes) in dead animals
Decay of rocks
Tracers
What is the Sun’s surface called?
The photosphere
What is the area outside the Suns photosphere called?
The chromosphere
What is the appearance of an absorption spectrum?
Black lines on coloured background
What appearance does an emission spectra have?
Coloured lines on a black background
How is the speed of sound related to wavelength?
C= wavelength*frequency
How do you get an atomic emission spectra?
Heat atoms in flame
Pass through slit
Pass through prism
How do you get an atomic absorption spectrum?
White light through heated atoms of element
Pass through slit
Pass through prism
What is the Lyman series?
The emission spectrum of hydrogen atoms in the UV region
What is Bohrs theory?
Atomic spectra caused by electrons changing shells
What is quantisation of energy?
Difference between sub-shells has a specific energy for an element
What is a dative covalent bond?
Both electrons from the same atom
What is electronegativity?
Measure of the ability of an atom in a molecule to attract electrons in a chemical bond to itself
What is metallic bonding?
Lattice of positive ions and pool of delocalised electrons
What is the shape and bond angle in a five atom compound like CH4?
Tetrahedral
109 degrees bonds
What shape is ammonia?
Pyramidal
What shape is water?
Bent
What is the shape and bond angles of BF3?
Planar triangular
120 degrees bond angles
What is the shape and bond angles when there are five groups of electrons around a centre atom?
Trigonal bipyramidal
120 or 90 degrees bond angles
What is the shape when six groups of electrons around the central atom?
Octahedral
What are the group 1 metals called?
Alkali metals
What are the group 2 elements called?
The alkaline earth metals
What do group 2 elements form when they react with water?
A hydroxide and hydrogen
What is formed when the group 2 oxides and hydroxides react with acids?
Salts and water
What is formed when heating group 2 elements carbonates?
Oxides and CO2
How does group 2 element solubilities change?
Increases going down for hydroxides
Decreases going down for carbonates
What is the atomic number?
The number of protons
What are feedstocks?
Starting materials