C2.3 Flashcards
What can relative masses of atoms be used to calculate
How much can produce and how much can react
Why can u wok out how much produces and how much react
Because no atoms are gained or lost in chemical reactions
What is the atomic number
Proton number
What is mass number
Bigger number or neutrons and protons
Mass of proton
1
Mass of neutron
1
Mass of electron
Very small
What is an isotope
Same elements with different neutrons
What does the relative atomic mass compare with the mass of an atom
Carbon 12
What is carbon 12
An average value for the isotopes of elements
What is relative formula mass
Sum of relative atomic masses of the atoms
What is a mole
Relative formula mass of a substance
How big is a mole
6x10^-23
How are elements and compounds identified
Using instrumental methods
Why are instrumental methods better than other methods
Accurate
Sensitive
Rapid
Detect small substance
How are additives in foods identified
By chemical analysis
What can be detected by paper chromatography
Artificial colours
An example of an instrumental method
Gas chromatography linked to mass spectroscopy
What can be used to help identify a substance
The time taken for the substance to travel through column
What can gas Chromatography be used for
To separate a mixture from compounds
What does a mass spectrometer do
Give relative molecular masses
What is the process of gas chromatography
Different substances carried by gas, travel through a solid packed with a solid material at different speeds so can be separated
How can u tell the number of compounds present
Number of peaks on the output of a gas chromatography
What is retention time
Position of the peaks on the output
