1.1 Atomic Structure Flashcards
Which number is used to represent the atomic number of an atom
Z
What does the atomic number tell us about an element
Atomic number = number of protons in an element
What number represents mass number
A
How is the mass number calculated?
Mass number = number of protons + number of neutrons
What are the isotopes of an element
Different forms of the same element, containing the same number of protons but a different number of neutrons. They still have the same chemical properties
How many orbitals do these shells contain?
A) 1s
B) 2p
C) 3s
D) 3d
E) 4s
A) 1s - 1 orbital, 2 electrons
B) 2p - 3 orbitals, 6 electrons
C) 3s - 1 orbital, 2 electrons
D) 3d - 5 orbitals, 10 electrons
E) 4s - 1 orbital, 2 electrons
Does 3d or 4s have the higher energy
3d
What is an orbital?
A region around the nucleus that can hold up to two electrons
What would be the relationship between two electrons in the same orbital in terms of their spin?
Have opposite spin as repel each other as both are negative (spin paired)
Explain why Chromium does not fit the trend for electronic configuration
It only has one electron in 4s before filling the 3d orbital
1s2….. 3p6, 4s1, 3d5
Explain why copper does not fit the trend for electronic configuration
It only has one electron in the 4s orbital before filling the 3d
1s2…. 3p6, 4s1, 3d10
What are the two types of ionisation for a mass spectrometer? How do they differ?
- Electron impact: electron gun (hot wire filament with current through it emitting electrons) knocks off one electron from each particle to create 1+ MOLECULAR IONS (these ions fragment)
- Electrospray: sample dissolved in volatile solvent (e.g. water or methanol) and injected through a fine hypodermic needle to give an aerosol. Needle attached to positive terminal of high voltage power supply and particles gain a proton from the solvent as they leave the needle, producing XH+ ions (+1 charge and Mr of +1) (ions rarely fragment)
