Where alchemy beacme chemistry Flashcards
what did dalton discover about atoms and what year?
1803, discover atoms are invisible, small spheres. (solid sphere model)
what did JJ thompson discover about atoms and when?
1904, discoverd electrons in atoms scattered through spherical positive clouds. (plum pudding model)
what did Rutherford discover about atoms and when?
1911, fired positively charged alpha particles at thin gold foil, passed through at angles, mostly empty space in atoms positive charged centre nucleas. (nuclear model)
what did Bohr discover about atoms and when?
1913, stated electrons orbit around nucleas. (planetary model)
what did Schrodinger discover about atoms and when?
1926, electrons dont move in set paths but in waves. (quantum model)
what is an alpha particle
a helium nucleus emitted by some radioactive substances, originally regarded as a ray.
what is protons’ mass, charge and location?
mass= 1
charge= +
location= nucleas
what is neutrons’ mass, charge and location?
mass= 1
charge= 0
location= nucleas
what is electrons’ mass, charge and location?
mass= 1/1840
charge= -
loaction= orbiting nucleus
what are noble gases?
Any of group 18 that includes helium, neon, argon, krypton, xenon. they have full outer shells and unreactive
what is electron configuration
Describes how electrons are distributed in its atomic orbitals. it goes 2,8,8/18
what is an isotope
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nucleus
what are radioisotopes
An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable.
what does monoatomic mean
means it is a single atom
what is the reaction in group 1 metals
group 1 metals are very reactive cause they have 1 electron in the outer shell. lost easily
why do group 1 metals become more reactive down the group?
valence electron get further away from the nucleus= harder to hold on.
what is lithium’s physical properties
dark/ stiffer to cut/ shiny when cut
what is sodium physical properties
pale grey/ easy to cut/ shiny when cut
what is potassium’s physical properties
pale grey/ silver/ easy to cut/ soft
what is sodium reaction with oxygen
4Na + 02 –> Na20
what is lithium’s reaction with oxygen?
4Li + 02 –> 2Li20
what is potassium’s reaction with oxygen
4K + 02 –> K20
what is a halogen
elements fluorine, chlorine, bromine, iodine, and astatine, in group 17 of periodic table. Reactive non-metallic elements that form strongly acidic compounds with hydrogen from which simple salts can be made.
what is a displacement reaction
more reactive halogen atoms react to displace less reactive halide ions. halide ions lose electrons
