2.2 ATOMS, IONS AND COMPOUNDS Flashcards
What is the mass and charge of protons, neutrons and electrons?
Protons- mass= 1
- charge= +
Neutrons- mass= 1
- charge= 0
Electrons- mass= 1/1836
- charge= -
What is the mass number and atomic number?
Mass number is the number of protons and neutrons.
Atomic number is the number of neutrons.
What are isotopes and what are examples of useful ones?
Isotopes are different forms of the same element with the same number of protons but a different number of neutrons (that have the same chemical properties but different physical properties)
- carbon-14 = dating wooden objects and animal remains
- uranium-235 = fuel nuclear reactors
- iron-59 = anaemia diagnosis
What is the relative atomic mass?
The relative atomic mass is the weighted mean mass of an atom of an element relative to 1/12 the mass of an atom of carbon-12
What is the relative isotopic mass?
The relative isotopic mass is the mass of an isotope of an element relative to 1/12 the mass of an atom of carbon-12
What are the steps of a mass spectrometer?
The steps of a mass spectrometer are:
1. vaporisation- sample vaporised so it is not solid
2. ionisation- electrons passed sample to form positive ions (chamber vacuumed)
3. acceleration- ions accelerated so all have the same kinetic energy
4. deflection- ions deflected by a magnetic field according to mass
5. detections- ions detected
What are uses of a mass spectrometer?
Uses of mass spectrometer:
- abundance of isotopes
- identifying unknown compounds
- analysing molecules in space
How do you work out relative atomic mass?
Relative atomic mass = (mass number x %) + (mass number x%) + etc… / 100
What are the state symbols?
State symbols:
- solid = s
- liquid = l
- gas = g
- aqueous = aq
What are the group charges?
Group charges:
- group 1 = 1+
- group 2 = 2+
- group 3 = 3+
- group 4 = usually covalent
- group 5 = 3-
- group 6 = 2-
- group 7 = 1-
- group 8 = full outer shell, unreactive
