Chapter 2 - Atoms, ions and compounds (MODULE 2) Flashcards
What two subatomic particles are located in the nucleus
protons and neutrons
Where do electrons exist in an atom
in shells around the nucleus
What are the relative masses of each subatomic particle
protons: 1
neutrons: 1
electrons: 0
What are the relative charges of subatomic particles
proton: 1
neutron: 0
electron: -1
How do neutrons benefit the atom
holds the nucleus together, despite the electrostatic forces of repulsion between protons
How is the periodic table organised
in order of atomic number (number of protons)
What are isotopes
atoms of the same element but with different amounts of neutrons
How are isotopes represented in chemical notation
with mass number, atomic number and chemical symbol. Alternatively can be shown with just mass number
do different isotopes of an element have different reactions
no
What is heavy water
water with the isotope ‘deuterium’ of hydrogen, which has a mass number of 2
What are ions
a charged atom, with a different amount of protons and electrons
What are cations
positive ions, which have fewer electrons than protons
what are anions
negative ions, which have more electrons than protons
Why can’t mass of atoms be measured simply by adding masses of all the subatomic particles
because some mass is lost due to the strong force holding the nucleus together
How is atomic mass calculated
‘u’ - the mass of 1/12 of an atom of carbon-12. this is a standardized unit
Why does relative mass have no unit
because it is the ratio of two masses
What is relative isotopic mass
the mass of an isotope relative to 1/12 of the mass of carbon-12
What is relative atomic mass
the average mass of an atom relative to carbon-12, weighing in all isotopes of the element
how can finding percentage abundances of isotopes be done experimentally
by using a mass spectrometer
What is the basic method that mass spectrometers use
- place sample in mass spectrometer
- vaporise and ionise sample to make positive ions
- accelerate ions. Heavier ions move slower and so isotopes are separated
- ions are detected on a mass spectrum as a mass: charge ratio
what is the calculation to work out relative atomic mass
100
How do atoms on the left of the periodic table react (electrons)(ionic)
lose electrons and become cations
How do atoms on the right of the periodic table react (electrons)(ionic)
gain electrons and become anions
What charge do different atoms produce
group 1 - (1+)
…
group 7 (1-)
group 8 - (0)
transition metals can form several charges
