Chapter 1

Questão	Responda
Mass of: Proton Neutron Electron	Proton: 1 Neutron: 1 Electron: 1/1840
Charge of: Proton Neutron Electron	Proton: +1 Neutron: 0 Electron: -1
Nucleons	Particles in the nucleus of an atom
What are nucleons held together by? What does this cause?	Held together by strong nuclear force Releases large amounts of energy during nuclear fission
Ion	Atom that looses or gains electrons
What is a mass spectrometer?	Most useful instrument to accurately measure RAM and amount of each isotope
Which is the only atom with an isotope with an RAM that's an even number? Why is this?	Carbon-12 Neither protons or neutrons have a mass of exactly 1
What does a mass spectrometer do?	Measures the mass of separate atoms
When is mass spectrometry used in real life?	By forensic scientists to identify different substances
How do mass spectrometers separate different isotopes?	Separate ions by mass:charge ratio
What are the 4 stages in a Time of flight (TOF) mass spectrometer?	Ionisation Acceleration Ion drift Detection
What condition does a TOF spectrometer have to be in? Why?	A Vacuum To prevent ions colliding with molecules in the air
What happens during the Ionisation stage in a TOF mass spectrometer? (Electrospray ionisation)	Electrospray ionisation: sample dissolved in volatile substance :Forced through fine needle :To a positive terminal of high voltage :Tiny +charged droplets :Solvent evaporates until single positively charged ion is produced
What happens during the Ionisation stage in a TOF mass spectrometer? (Electron impact)	:Sample vaporised :High energy electrons fired from electron gun :Knocks off 1 electron from each electron forming a 1+ ion
What is an electron gun made from?	hot wire filament with a current running through it
What happens in the acceleration stage in a TOF mass spectrometer?	+ions are attracted to a -plate and accelerate towards it Lighter and higher charged ions accelerate faster
What happens in the ion drift stage in a TOF mass spectrometer?	:Ions pass through hole in -charged plate :Forms a beam :Travel along a flight tube :To the detector
What happens in the detection stage in a TOF mass spectrometer?	:Ions of same charge arrive at detector :Flight times recorded :+ions pick up electron from detector :current flows
What is an isotope?	an atom of the same element with the same number of protons and electrons but a different number of neutrons
What is a principal quantum number?	The amount of orbitals (shells) an atom has.
What is the Heisenberg uncertainty principle?	You can't know where an electron is and its speed and direction
What shapes are the orbitals?	s- sphere d - dumbbell p - various f - various
What can each orbital contain?	2 electrons in an opposite spin
What are electrons?	Cloud of charge/wave
What is different about the electron configuration of copper and chromium?	Steal from 4s to make 3d
Why do sub-levels overlap?	As you get further from the nucleus, principal energy levels get closer together
How do electrons move levels?	They are promoted to a higher level by quanta which is a packet of energy
What happens when electrons come back down from promotion?	A photon is released which produces colour
Why can zinc not be promoted?	It has a full 3d sub shell
What is 1st ionisation energy?	Energy required to remove an electron from the outer shell of one mole of atoms in their gaseous state
What is the affect of Charge on nucleus on IE?	:More protons :Higher charge :More energy needed to remove electron :Higher IE
What is the affect of distance of electron from nucleus on IE?	:Bigger distance :Lower attraction :Less energy needed :Lower ionisation energy
What is the affect of amount of shielding between outer electrons and nucleus on IE?	:More quantum levels :More shielding :Less energy needed :Lower ionisation energy

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	Criado por Bethany Westwood aproximadamente 8 anos atrás